thats true.
we had one brave dev port the darn thing WITHOUT source code to the triumph. and its one of, if not the best, rom we have for the phone.
although CM7 came a long way, CM7 now has a bunch of the features MIUI has (advanced settings like changing carrier name and status bar stuff, lockscreens, yadda yadda) and CM7 now officially has screen rotation and better animations.
to miuis credit, I have never, ever seen a CM7 rom on any of my devices work so smoothly. every little detail from scrolling home screens to switching between apps is polished with animations and clean pixel perfect icons and details.
MIUI really makes a HDPI screen look amazing. especially if the screen isnt capped at frame rates, like the EVO is. then it looks super smooth like a iPhone. if youve ever just played with an iPhone and noticed how every little action is done perfectly, no lag switching screens or stuff. thats how it is.
I think part of that is becuase most of the HDPI phones actually have the cpu and gpu power to back that up, and miui takes full advantage. thats why I dont think the OVs mini snapdragon will handle it as well.
however, I will be watching what happens, because I've been surprised before.
*edit.
when comparing my Triumph screen to the OV, it seems like the OVs screen is either under 60 fps always or has motion blur, like pixels not switching fast enough. i mean i never noticed it until I had a better phone, but side by side, its noticable. the triumph screen, and many other hdpi phones, with a nice rom, feel like watching a 240Hz HDtv where everything looks super smooth and freaky. this is less of a comment about roms but more about the difference you get when you pay for good hardware rather than buying budget hardware. little things like that