Starting a door build with 3 of theses per door, once I put the other two in I will post another review but they get loud. Will be on a Hifonics zrx1200.2
I used four of these in a non-car stereo application, as ceiling mount speakers in my living room. Of course you can pay six times the money for "ceiling rated" speakers like the JBL LS328C but basically you pay for aesthetics; the sonic improvement will be nominal. I've listened to everything from Diana Krall to Dream Theater on these and the detail and bass response is very good. I wish they came with grilles but they don't. If you want a lot of high-end detail from them (+5kHz) you won't get it because according to the specs they sign off at 4600Hz. Wish they went to 6kHz like the RTX88s. Are they worth the money? I think so.