Best speakers under $500? Fire away!

"I think I have narrowed down my choices to the ELAC Debut B6 and Wharfedale Diamond 10.1.  Both are roughly $259 shipped and can be returned easily.  Sensitivity is 86/87db for both."

Keep in mind that because both are 6 ohm speakers, that sensitivity rating is for 1.5 watts. Correcting to a 1 watt rating will be 84.5/85.5.

OK... I think I have narrowed down my choices to the ELAC Debut B6 and Wharfedale Diamond 10.1.  Both are roughly $259 shipped and can be returned easily.  Sensitivity is 86/87db for both.  

Any input on which way I should go?

Buy them both, audition them with your system and keep the pair you like best.  Send the other back.

I have both the b6 and 10.2 . The Elac has a lot more wow factor, 10.2 is just as good.The b6 is a clear choice.

I would suggest that you consider improving your power first, which will open up many more choices on speakers.  Much of the high-end stuff we talk about here is fairly inefficient.

My recommendation would be to look for an amp that can push 100 watts per channel minimum, and use your NAD as a preamp (I'm pretty sure you have pre-outs) so you don't lose your investment.

Once that's done, if you're willing to look at pre-owned gear, have a listen on a pair of Dahlquist DQ10s.  They can be had for under $500 a set in excellent condition, are easily maintained and are still to this day considered a terrific value.  They are, however, highly inefficient.  ;-(