Ok so after ROM hopping for about about 4 weeks, I think I've found the one I want to stick with.
Cyanogen Mod was the second ROM I installed - I originally had Pinky, which is still the fastest I've tried so far for my Desire - it's also very stable. But was too restrictive, didn't really bring anything to the table over the original ROM. I tried CM 6.0.0 and didn't like it very much, it was laggier, less stable, sure it had more tweaking options but I couldn't handle the slower scrolling, worse battery and I loved the HTC sense widgets.
So I continued to hop about, mainly trying all the Sense based ROMs for my Desire. Approximately a week ago, I thought I'd give CM one more go... Boy am I glad I did.
I got the non responsive wakeup bug, and was not impressed and thought nothing had changed, fortunately there was help on the forums so I patched to 6.0.1.4, disabled all the transitions bloat, found the amazing Agenda widget, installed the Elegant ADW theme, and started to really get into the settings for the ROM, tweaking and setting up the phone to run exactly how I like.
The phone is now fast at scrolling, renders pages quickly, snappy at shifting through menus, predictable in the way it reacts, good on battery and handles just how I think a phone should. 6.0.1.4 is a large step up for Desire users. There is no doubt in my mind now that I picked the right phone, coupled with this ROM, I just love it. HTC have a new semi-regular customer! The funny thing is, I would've bought a Nokia if they had any decent smartphones out, they appear to have dropped the ball as of late though.
If you haven't tried this ROM, I highly recommend you do, if its supported on your phone. It may not be everyones thing, but nandroid does a pretty good job of backing everything up - nothing lost if you don't like it.
What're your experiences with CM6?