It most definitely will. The bass on the MS-2i is fantastic, especially with flats. And they certainly are not bright or shrill. If anything, I found the MS-2i to be lacking a bit of top end, which is why I sold them eventually. They didn't have the satisfying treble of the RS-1. But of course I've regretted selling them many times because of their ultra smooth sound, great midrange, and aforementioned awesome bass.
I preferred them with flats, but I prefer every Grado with flats aside from the GS1K (haven't heard the PS-1 enough to make a decision).