I can tell you one thing...Guys that used to training in GI play jj very "tight". I mean they are used to maintaining a very tight grip while going from one transition to another. Maybe it's even better to start your bjj with gi...just to have the feel of it...the feel of "tightness" of the game, the feel of good control over your opponent. Then you can move to no-gi and your game will only get better. I started with no-gi but it was damn hard for me at first, i had to learn to balance on my opponent which was hell of a lot harder than if i'd put my gi on. But despite all this bullcrap i can easily throw rubber guard on my opponents with or without gi. I'v heard Eddie say that gi developes bad habits like pulling by the collar while having your opponent in your guard but that's where your open-mindness comes into play. I would wear a freaking gi just to make it easier for my opponent to choke me, just to be more aware but i wouldn't use the advantages of my gi (except keeping my sweat of my face and stuff). My point is that gi means more control, more awareness. Gi doesn't make your game worse, but you have to be able to do just as well without the darn jacket.
P.S. Rickson trained without gi from time to time and don't tell me he doesn't know jiu-jitsu.