Probably just to do with air flow or even aerodynamics, especially if SR stands for Stamina Ring as it is basically confirmed to be on a couple of blogs out there, as well as having no gimmick other than the visible design one, and BWD standing for "Big Wide Defense" of all things.
http://ameblo.jp/remi-mayu-papa/
I should say that I found that link on the wikia page for the bey. Their increased use of referencing is a very positive thing.
Anyway, it has weights and some nice comparative pictures of the track/tip. BWD's tip angle looks slightly different to me, steeper, which I'm not so keen on, and I'm concerned about the side parts disrupting the usual precession WD provides.
SR200 will probably be a decent stamina track, 195 was a height I liked a lot with TH170 so 200 with the D125 gimmick should be quite nice.
Still, last I checked we don't even have a testing thread for Goreim yet, so it might be a while before we get much solid info :c