OP, that question has been haunting me for a very very long time - 65 or 68? I've tested each multiple times, and the 68CPR is more to my liking. The sound is warmer and fuller to my ears, and it is as mentioned previously, bass-heavy. Most 68 players keep that bass below 3. Another good idea with these amps is to keep them off the floor, that lightens up the bass. The 65 sounds nice and clear, but it is more treble-y, too much so for my liking. I also like the earlier breakup on the 68 as it just fills up the sound. Note of warning, some of the 68's come with cabinet rattle, but if you buy new that should not be an issue, I think it was trouble with some of the earlier ones. At 3-4 they start rattling like crazy. I tested one like that and other people have mentioned this issue. A 68 also greatly benefits from a speaker switch - Greenbacks and Cannabis rex are common choices. I have plenty of recorded demo's with each, and even with the Surf Green LE one with the Greenback speaker, if you'd like to hear them. Half a year ago I convinced myself that it'd be too loud for me so I got a Katana, but I've recently been thinking coming back around to the thought of a Princeton! P.S. If you haven't yet, watch Jack Fossett's demo of the 68 CPR. He does a really good review and good tone tips, as well as demoing with single coils and HBs.