you're not going through anything different then the rest of us. i promise you just about all of us have had some form of buyers indecision and/or remorse. heck, i bought all my ht gear in december and i'm still wondering "did i do the right thing?" (of course, with the deal i got, i have no complaints at all!
)
like i said elsewhere, try not to get hung up on specs. buy the receiver because it fits your needs, is flexible enough, etc. really, most specs are worthless anyway. if you can hear the difference between 10 watts and/or .02%thd, then you're in the wrong business.
the yamaha receiver is a fine receiver. i sell it all day long. i'm not knockin' onkyo or hk (which i've also owned and sold) - they're just as decent. but i can honestly say imho, i feel those three brands are neck-n-neck with eachother.
anyway, take a breather and enjoy your new toy for a while!
of course, let us know if you have any other questions!
whew.. hehehe you said it just right.. i have already upgraded the system thrice in 3 months..and i hope i have got it right this time. Just to share it.. earlier bought a hometheater in box from yamaha-didnot like it- bought polk rm6005 series with htr 5640, was good,when heard rm6700, the rm6005 sounded small so upgraded the speakers 
so i had to ask it here.. thanks for clearing the doubts and cheers to polk and yamaha and all of you who helped me out!