HTC Inspire 4g (international Desire HD)
that's one kicking phone for developement! Most people agree that the phone is long past it's due date, HTC has dropped major support for it (pretty much doesn't acknowledge it any more), but the developement is booming for it. The latest official release is android 2.3.5, but there are custom 4.2 ROMs even.
I'm rooted currently running Blackout ICS desensed- which is basically android 4.0.4 and sense 3.6, then with most of the sense stuff removed (mostly the launcher, rosie, and the widgets). I like HTC sense well enough, but I prefer the look of AOSP ICS so I prefer going desensed.
The I4g has 768mb of ram, and around 610mb actually accessible. It's a lot compared to some phones of the same age, but to modern phones it's nothing and you notice it. Usually I'll run the Supercharger script, which does wonders.
Cpu is 1.0 ghz single core. Sometimes I'll OC but not often (with sense ROMs I'll usually overclock to overcome the bloat, usually to 1.2 ghz or 1.3). I haven't noticed any changes in performance when OC up to 1.5, all it does is run my phone hotter. Certain ROMs for my phone can 'safely' (relatively speaking of course, YMMV) OC to 2.2 ghz, but again, no realy performance change from 1.2 ghz at first, and after that it really starts heating up and runs way slower- by then I'll have clocked back down and rebooted.