[Oxymoron238]

OP, did you flash stock before flashing some of the roms you tried? I ask because I had the same problem after I flashed the new Mightyrom, and for a while I was disappointed with the new Manila 2.5.

However, after I flashed stock and then flashed back to Mightyrom, I was impressed by the speed. Granted, it wasn't as fast as 2.1, but it was only marginally slower. I get pretty much no lag at all (and I promise you its not the ol' placebo effect, because I expected Manila 2.5 to be slow).

I did remove some graphics from the screen though ( I removed the weather background, calendar background, and quick link backgrounds from the home tab). Even with all quick links taken up and fullscreen weather animations running (not just enabled, actually running), I still get no lag.

So, my advice is, flash stock, then flash the newest Mightyrom. I think you'll be pleased.