Thanks, guys. You got me thinking... and as much as I hate that, it's why I asked.
This gets to the heart of replacing the receiver. The guy, (really nice guy), at Aperion suggested a better receiver would improve the sound of the Verus Grand Towers before I even bought them. I said ok, that will be my next step, and bought the VGTs and VGC anyway.
To me, they sound great, and the Yamaha has more than enough juice to drive them and the 4 KEFs. (I'm currently running 7.1, w/ the 2 subs simply split w/ a splitter cable.) Normal listening level is -25dB... -10dB for really cool loud HT stuff like The Return of the King... 0dB only when the boss is away as it hurts her ears, scares the cats and dogs, and makes me have to pee. (The FV15HP really is a "beast"!)
So it's not a question of volume. Not really even a question of the .2 separate controls as the Rythmik and KEF have enough controls on them that I think my T-shaped room is fairly well covered now, at least for our 2 seats.
It's really a question of sound quality, which only came up because Aperion said it would make a difference. In fact, they really didn't recommend these speakers with my Yamaha rcvr.
I've seen Pyrrho's sentiment expressed elsewhere... that there really isn't a difference in sound quality as long as you have enough power to drive your speakers. I'd hate to drop another couple grand and find I really can't tell a difference. So I'm still thinking.
Thanks for all the suggestions, guys!!!
There can be a difference in sound if you engage some special feature in one receiver and not the other, or if the features are not implemented in precisely the same way. My newer, more expensive receiver can automatically adjust equalization to make the in-room frequency response flatter, and engaging that affects the sound. But if I run it without such features, and have the settings all the same, it sounds the same. On paper, the more expensive receiver has lower levels of distortion and so forth, but the lesser one is low enough that there isn't any audible problem, and we are talking about levels far below what any speaker would have.
That equalizer function is nice and does, slightly, improve the sound. But my speakers are good and placed reasonably well, so it is not a dramatic improvement.
Now, if you have carefully set up your system, and if you have dealt with any major room acoustic problems, if you want a real change in sound quality, it must be done with speakers. Most people do not spend their money wisely, if maximizing sound quality is the goal. Speakers matter far, far more than anything else. This is because, compared with anything else (well, good digital sources anyway), the speakers are the source of most of your distortion and frequency response issues and other problems. My $6000+ speakers combine to give me a frequency response of about 15-40kHz +/-3dB (excluding room effects), which is really good for speakers, but crap for an amplifier (which should have a much tighter tolerance, and also won't have a frequency response that drops like a brick beyond those limits). And the distortion is something I do not entirely know with my speakers, as speaker manufacturers typically don't give that sort of information, because it is bothersome to measure and mostly because all speakers are crap for distortion compared with any decent amplifier. And also, the amount of distortion a speaker produces is typically related to how loud it is playing, as speakers tend to distort more the closer they are pushed to their limits.
One reason that people misspend their money is that it is easy to see additional features that one receiver has over another, and it is easy to see numbers in power ratings and so forth, and so people want to get a better one. But with good speakers, it is harder to see and point to what it is that makes the one better than the other, at least in many cases. Sure, you can look at frequency response and a few other things like that, but it will not tell you the whole story about which one is better. With the limited specifications that one typically sees, one can easily encounter two speakers with very similar specifications that sound very different from each other, but in such cases, it is hard to point to what it is that makes the one better than the other.
As far as that guy from Aperion is concerned, every company wants to blame any problems with the sound of your system on something else, and he wants you to imagine Aperion speakers are better than they are, and if only you would spend crazy amounts of money on esoteric other gear, you would fully realize the speaker's potential. If he can convince you of that, you are likely to believe you really do hear improvements after replacing other things, as people are very suggestible, and also after making a change, people often listen more intently than they did before the change, so of course they then hear more details than they heard before! (Not to mention the fact that when changing things around, people often slightly reposition their speakers, which can affect the sound by itself.)
Now, if you are not happy with the sound of your system, you should ask yourself what, exactly, it is that you are not happy about. Is it deep bass? If so, then look to your subwoofer situation. Is it clarity of dialog, or an aspect of the sound other than the deep bass? Then it is a question of the relevant speaker(s). If the problem is only when it is playing loud, then it could be either that the speakers distort too much at high volume (which is common enough, and will happen at some point with any speaker, though one hopes to have some such that it will be at a higher volume than one ever needs), or it could be that the amplifier isn't powerful enough for those speakers in that room for the volumes you require. But it is hard to tell which of those it is; one normally "tests" this by replacing one or the other, often by putting in a much more powerful amplifier to see if that satisfactorily deals with the problem.
Most people, though, are just dealing with speakers that are not ultimately satisfying, and so they are constantly trying to do something to get better sound. Well, the solution for them is to get better speakers, which is much easier said than done. Really good speakers usually cost quite a lot of money, and people don't want to face that, hoping that a less expensive option will cure their problem.
If you want your money to go into giving you the best sound you can get, put your money into your speakers, and as little as you reasonably can into the other gear. How little that is depends greatly on the particular speakers selected; I am far less lucky about the needs of the speakers for my main 2 channel system than for my home theater;
here is what I use for my main 2 channel system. But even there, I use very ordinary wires and CD player, with a capable but not esoteric amplifier to drive them. They are very "revealing" speakers, and yet they are really the weak link in the chain of my two channel system. Everything hooked up to them has a flatter frequency response and lower levels of distortion. If I used a home theater receiver with them to try to drive them, that would likely be a problem, as they are not efficient and are 3 ohms nominally, and so I need a better than average amplifier to drive them. Even though my speakers are very nice, your "cheap" Yamaha receiver, if used within its design limits, will provide a much flatter frequency response and lower levels of distortion. That will be true no matter what speaker we are talking about.
There is, of course, another issue in audio, and that is the fact that there are some people who are not satisfied, no matter how good their gear is. They have a real problem, but the problem lies in themselves, not in their equipment.
If you have properly set up your equipment, and if you have dealt with any serious room acoustic problems, and if your receiver can adequately drive your speakers, your speakers are the weak link in your system. And it will always be that way, no matter how much money you put into speakers.
