I am not sure if this has been mentioned in this thread but I just flashed to the 28205 Sense 2.5 Sprint rom and love how snappy it is but still miss the MMS ability of Sense 2.1.
I found this thread and did what was suggested and it worked on this ROM (
http://forum.ppcgeeks.com/showthread.php?t=104531). It is not the perfect fix but it is pretty damn close I think.