keep in mind that with the 3808 there is two seperate places to adjust speaker size. One is for surround mode and the other is for direct/stereo 2 channel listening.
If it is set up with audessey It should change them both, but if you do things manually be sure and keep that in mind.
Also, I don't see how the vase could impact the sound at all.
I do have it set to large with no sub in the 2 channel section. I may change that later to add sub but I wanted to run all sound through the M60s for a few hours. I've seen some comments that you need a break in period and some say they are already broke in when you receive them.
Whoever said you can tell big differences between different sources it right. I have some mp3s (I know they aren't ideal for great sounding music) ripped at 320 and 256 (which in theory is CD quality) and some like For Abbey and Mr. B.K by Ronnie Earl and the Broadcasters sound great while some of the others sound like an AM radio
