I'd imagine that the Aikido Gi has the longer skirt on the jacket so it will stay tucked in the Hakama better...maybe?
I always have a field day with guys that have loose baggy, and long Gi's in BJJ. They make wonderful garrots to wrap around the neck and to secure arms with!
I have an Atama Single weave that I have worn for the past 3 years. Decent GI, starting to wear and tear some, but it has been my favorite!
I also like the Gameness Double Weaves, but you have to be careful if you are going to compete under IBJJF rules, the Collars are too thick sometimes and they are not legal!