I dunno...I wouldn't call them a huge improvement - hardly noticable, IMO. It does launch better and feels better on high speed turns, but 'huge' is a big word...
I had Kenny Brown Super Subs (regular length) on my 01 and have MM regular length subs on my 03 and felt more of a difference with the Kenny Browns. I didnt feel too much with the MMs. Could just be all in my head.
I noticed a pretty substantial improvement after my MM full-length SFCs were welded on. Driving the car before and after was like night and day, at least to me...regardless, they are a great suspension/chassis mod.