The bjj school I trained at was a kimono/no kimono school. We probably trained 65% no kimono, 35% kimono. To be honest, I prefered no kimono but strictly for vain reasons. I'm a heavy, strong guy so with no kimon I could use my strength and weight against opponents much better when I didn't have to worry about getting caught with some type of kimono choke. While I understand that speaks to my technique, or lack there of, I also think that as much as I shouldn't count only on my strength, smaller people shouldn't count only on kimono techniques to get them out of jams. While I prefer no kimono, I think you should train both so that you at least have a perspective on how technical the game is with one, and how much more strength plays into it without one. No expert here, but just my 2 cents.