Statistically, there seems to be more more shavers happy with the Slim, but only by a "slim" margin. So, I bought one on eBay. Still waiting for it because of the Canada Post strike. The margin is so "slim", that it amounts to personal preferences.
I have them all, even the shorter black handle one, out of all of them i Love the slim, all the time i had it in my collection and never tried it, so one day i go on vacation and take a few with me, even a Nice barbasol one, let me tell you for the the slim was one slick shave. first i do a pass at 5 then 4 Nice BBS for sure.