I recently purchased the 74TXvi and couldn't be happier. I demo'd the 2600 and 72 at home for about a month and leaned towards the Pioneer. That said, I knew Pioneer was releasing the 74 soon and decided to wait on it.
Given the month or so I've had it, I feel I can comment on some of your questions:
1) Is there any difference between 74TXVi's HDMI switching and that of the 2600? Perhaps Yamaha does better upscaling?!
They both look poor compared to pure HD (720/1080).
2) THe power specs are almost identical (Yam. 130, Elite 140) - however the THD at these is Yam. 0.04% vs. Elite 0.09%. Is the THD actually comparable? If so, the Yamaha seems to have the lowest of any manufacturer incl. the HK models.
Oddly enough the bright sound of the Yamaha leaves the impression it has more distortion (at higher volumes) than the Pioneer.
3) I don't care too much about the DSP modes, but would like some kind of virtual surround sound for the headphones (such as HK's Dolby Headphone)... do the Yamaha and Elite models have something like this where they simulate 5.1 speaker setup on 2-channel headphones?
Pioneer has something that's called "PhonesSurround". Sounds good, but in my opinion, not as good as Dolby Headphone - which I've only heard through my HTPC.
6) From reading, I've gathered that the Elites sound warmer than the Yamaha's which are brighter. Warmer means "mid-rangy", and brighter more treble in your face - is this a correct interpretation?
I didn't think this was the case with the Yamaha until I heard it side-by-side. When I put my Paradigm Studio 60's in the mix, the yamaha was even brighter. I re-cal'd with little change. On the flip side, the aditional brightness from the Paradigm's balanced out the Pioneer, both the 72 and 74. Guess you know what speakers might work for you if you get a 74!
7) The Elite is iPod and iLink ready - both are somewhat attractive... The 2600 does not have them
That was a feature I wanted, mainly for SACD/DVD-A connection purposes. Kind of useless once I really looked at the market for a i.Link capable player. Pioneer only has that feature on their high-end player, which if plugged in by i.Link, would bypass the superior converting of the player. Kind of silly to do that. There are cheaper players with i.Link, however, the converters likely are better in the player than the 74 - which again would be silly not to utilize. i.Link, simply passes the raw uncompressed signal to the receiver for conversion. But if you have another use for i.Link....
8) Elite's auto-calibration systems seems to be the best of all the receivers out there (esp. on the 74 model which also has phase adjustments) - is it actually true that it is much better than YPAO from the 2600?
Pioneer has received much positive feedback on their MCACC system. It works! I can tell you that both the 72 and 74 nailed the measurments dead-on. The 74 also has a great interface for the PC so you can really see what's going on (need to download software from Pioneer).
9) Elite has a USB connection - from what I understand you can plug a USB cable to your comp. and the receiver can decode your mp3's (rather than letting the comp. sound card convert it into audio). If this is true than I should expect much better sound quality from my mp3's when played throgh the 74TXVi...
I bought a Creative X-Fi sound card. I have been going digital coax to the receiver and it sounds amazing. I tried the USB connection and found I got pretty much the same result. Not better, not worse. The issue for me was the receiver is better than 30' away and too far for a USB connection. The digital coax run is perfectly happy at 30 feet. If you have a HTPC nearby, the USB connection would kick ***.
10) Bad remotes and the physical look mean nothing to me so I don't care about which is better.
Well I care, and the Yamaha remote looks well out of date. Receiver-wise, they both look great. Pioneer has a silver model of the 74 but it looks cheap. Nothing beats the high-gloss Elite.
Personally I plan on using it about 2/3 of the time for music and 1/3 for movies. Most of the music is from my computer and will be connected via a coax (or a USB in case of the Elite). Unfortunatelly the Elite only has 2 coax inputs...
Funny, that's exactly what I use it for and eactly the same feeling about the coax. What really sucks is my sat only outputs coax. Therefore both coax inputs are used now. Thankfully, the dvd uses optic and also 6-channel discrete. Only 2 coax inputs is probably my biggest gripe.
OK - enough from me. Basically I'm wondering why the Elite 74TXVi has gotten almost no mention on this site when from the points listed above it seems to be a slightly better receiver. Sometimes I think that this site may be sponsored by Yamaha, since its always recommended... just kidding.
In my experience, and being new to this site, you'll likely find that each site leans one way or another. There are sites out there that lean heavily to the Elite line, even the Pioneer reps are members! There are certainly other sites out there that dismiss Yamaha and Pioneer altogether in favor of NAD and Marantz. That's just the way it is.
Good luck with your purchase. One final note, look at your speakers and make sure the receiver will work with them. I found a few 4 ohms that likely won't do well with the Pioneer.
