I have added No Rez to:
a pair of AV123 X-CS',
a pair of X-SLS',
an X-Voce,
a pair of Klipsch Heresey II's
and a pair of Definitive Technology Studio Monitor 350's.
I have heard instant, worthwhile improvements in all of them. The Hereseys were night and day differences since they have zero bracing. The main thing you'll notice is a step up in clarity as it just gets the sound of the box out of the way.
And when you're ready for more, consider the Ninja upgraded crossovers. The stock crossovers are good but the Sonicaps take these speakers to a level that's just obscene for the money!
When I first got my XCS Classics they sounded nice but noticeably not as good as my SLS Encores. That Encore tweeter is a major upgrade over the classic version. Adding the Elite crossover upgrade package with Sonicap Platinums blew my mind away! They now remind me of some $3,000pr monitors I've lusted after. Total actual investment was under $500 for the pair! (I got the xcs' as c-stock for under $100/pr due to crappy veneer)
Sorry if I'm gushing but I'm a big fan of Danny, Sean, and Mark's efforts. Currently waiting for new crossovers for my SLS' and Voce.
