Re: Aikido Works
In the BJJ i am studying, we will roll very slow for 3/4 of the class, and then spend approximately 15 to 20 minutes in "randori" (rolling). I think it is easier to do in BJJ and Judo because of the nature of the skills you are training. Much harder to do with aikido and still be accomplishing the goals of aikido. Those are my experiences.
I think you do have to be very cautious not to reinforce bad habits in aikido. The dynamic is slightly different from judo or bjj, IMHO.