Looking for speaker recommendations that I can purchase on Amazon.com

A system only as good as its weakest link!

My Yamaha P5000S power amp doesn't sound anything like the Yamaha A-S801 integrated amp in my opinion. So maybe comparing it to a Yamaha A/V receiver wouldn't be appropriate.

I sent the 801 back and kept the P5000S.

The Yamaha P5000S even makes my Polk RTi A7's sound good to me! :-)

Look like we shared the same experience:
Speaker sound better with better amplification!

With all due respect here, troll or not, your wasting everyone's time here, including your own and I'll explain why in just a moment.  I apologize in advance for the harsh way this must sound, but my comments are meant  in a positive way so that you re-think what you are doing here.

1.  You recently wrote, "With so many recommendations for the KEF LS50, it seems like I need to give these a try. I had my mind set on floorstanding speakers initially, but after reading all the recommendations for the LS50 here, I think I will give them a try first.

Even if I still end up buying floorstanding speakers for my music room, I can then put the LS50 in my smaller home theater room to replace my Polk RTi A3’s.

I will call a nearby BestBuy store before buying the LS50 on Amazon. "

So why not just buy them from Best Buy and support the local economy and the person whose time you just wasted?  Instead, you're going to waste the salesman's time listening to them at his store and then buy them on Amazon.  (and please don't insult my intelligence and tell me you said above that your just calling Best Buy and not going there to listen to them - then what's the point of calling them?  Of course you're going to go there and listen to them, so let's be honest)  

2.  In reading through this thread, it's apparent that you've spent a great deal of time researching, reading reviews, and listening to everyone else's opinions except your own.  Trust your own ears!  They are no better or worse than a reviewers.  A reviewer might say one thing that sounds very encouraging but when you hear it, you may not like it.  Listen more, read less.  

3.  And this should be #1 - Your using a frigging 500 wpc, 26 lb Yamaha amp that is designed for professional use in a night club, bar or gathering hall.  Why?  This website is primarily for home audio, not professional audio, and I'd bet 95% of us, myself included, know nothing about professional audio but can talk to you all day and night about home audio.  I'll bet my old B&K EX442 at 200 wpc into 8, 360 into 4 and 75 amps would smoke that Yamaha for breakfast, lunch and dinner any day of the week.  Why? Because I once heard it up against tube monoblocks from Paoli (a highly moded Dyna mkIII) and you virtually couldn't tell the difference.  

4.  23' x 21' is a nice sized room, but how loud do you listen that you need 500 wpc?  You would be really surprised to hear how loud 1 watt can sound with the right speakers.  Get rid of that Yamaha and look for a tube amp because once you hear the warmth and sweetness of tubes, you'll never be truly happy listening to solid state, IMHO.  

You'll need something of decent power in a tube amp, unless you go with a single ended amp and high efficiency speakers.  If you've never heard a low powered SET amp with hi efficiency speakers, you are in for a treat and your journey will end there.  I once heard a 3 wpc 2A3 amp with horn speakers completely fill up a 40' x 40' room that you were completely satisifed with the loudness of it.  

Otherwise a push pull tube amp using KT88's or 6550's, possibly EL34's will get you where you need to be but I much prefer the SET sound to PP.

Go get the KEF's and see how it mates with the Yamaha for now and then consider upgrading the Yamaha which to me is the weak link here.  Let us know what you think of the KEFs.  Thanks for listening.

certainly agree to not take up anyone's time, either on phone, email or in person, if you have no intention of buying from them. unfortunately too, other places have much better prices on many of these recommended speakers

No one participating in this thread will ever get their time back. Yes, I do see the irony in my wasting a moment on it too. But it had to be said.

at least it was your choice :)