Is that kind of info typically published (other than in very detailed reviews like one your provided....thanks!), particularly for a receiver and not a separate? They probably don't expect many users to be concerned about that, as most people will just use the built in amplification and be happy.
But that's basically what I was wondering...if there's a difference from one pre-pro option to another, beyond software and compatibility, as it seems that most of the pre/pro-relevant published specs revolve around that.
There are differences in performance, but often the differences will not be audible. For example, once the frequency response is so flat that it is impossible to hear any deviation at all, then better will not be audibly better; once the noise floor is so low you hear no noise, a lower noise floor will not be audibly better; etc.
You can find out about detailed specifications generally by downloading owner's manuals for the products you are considering, and you can find actual performance from detailed reviews in which measurements are taken, if there are any such reviews of whatever it is you are considering. With Yamaha, I believe you will need to register with them to download their manuals, but it is free.
However, in most cases, you can buy based on features desired, inputs, etc., because most of the time, you will not actually hear any difference between two respectable preąmps/processors, unless you engage a feature that affects the sound (of which there are typically many).
Yamaha is a particularly good choice in some respects, as they tend to be very reliable.
Now, there is a "reason" to go with a separate preąmp/processor, and that is that snooty audiophiles hold their noises up at the idea of receivers, because they believe that putting things in separate boxes instead of all together magically makes things better. So if impressing people of a certain type is the goal, you will need to go with something other than a receiver.
I personally would probably go with a Yamaha receiver, as I generally like their features, and they tend to be very reliable, which matters very much to me. And if not all of your speakers require extra power, you can save money by using some of the built-in ąmplifiers. Some people, for example, use them for the surround channels, and just buy a power ąmp for the front speakers.
As I do not know what speakers you are using (or how loud you want things to be, etc.), I cannot comment on whether you need any extra power or not than what will come with a receiver. If you don't need any extra power, then external ąmplification is a waste of money. But if you do need it, then, obviously, it isn't waste of money.
In my case, I have easy to drive speakers in my home theater, so I just use a receiver for them. For my main 2 channel stereo, I have 3 ohm speakers which I drive with a separate power ąmp. If you need an ąmp, you need one, but if you don't, then it is a waste. Remember that before parting with your money.
You might want to read this thread about power output:
AVR Power Output Comparison
If you read down far enough into it, you will find that separate power amps don't always do better when tested.
