One of the reasons I ask is that I was looking at some online retailers and they had the RA series at a higher list price. I thought this was funny because DLS web site clearly states the Ultimate line is their top line.I personally prefer the reference series... something about them just sounds better to my ears. i don't want to spark another Amp SQ debate, just offering my humble opinion. And at the lesser price, you can't go wrong. And the cosmetics are more appealing IMO.