I currently own both of these heads. Just wanted to give my opinion on this and see if it makes sense to anyone else. I'm actually trying to decide which one I'm going to send back and which one I'm going to keep. I tested both of these through a Aguilar GS112, Avatar Neo 410, Bergantino AE212 and Ampeg SVT 410HLF using a Highway 1 Jazz w/Aguilar 70's pickups, 2010 American Deluxe P, L2000 and Stingray 4HH. Tone is subjective, but I can get a nice tone out of either of these amps. The RH450 is a little warmer due to the hi-pass filter and the Ampeg , while also warm sounding , can also go into hi-fi territory. Both amps sounded good with the GS112 and Avatar 410 and 410HLF. The RH450 honestly did not sound good at all with the AE212. I don't know what it was, but it just wasn't happening. In contrast the PF800 really came alive with the PF800. Probably the best match for the PF 800 that I've found so far, but I still haven't tried it with my Heritage 810 Now i've heard all about how TC uses some magic with the RH450 to make a 236 watt amp sound like it's 450 watts. This is what I found and the main reason I started this thread. The RH450 to my ears is probably every bit as loud as the 800 watt Ampeg. However, when I crank the Ampeg, I can really feel it moving some air. The RH450, while plenty loud, does not really seem to be really pushing the speakers. So perceived loudness does equal real power ? Does this make sense to anyone else or am I crazy ?