So I have a couple friends who I've done Entralinks with, and the abilities are rather useful, even with the three minute limit.
The one I use the most is Exp. Power +++ for 4 orbs (which isn't hard to get if you repeat item missions, nor is it hard to gain levels this way). It seems gimmiky, but level 3 doubles your exp, put that with Lucky Egg and/ or trade bonus and training becomes much easier. I have white so it helps make up for the lack of Black City. Right now I'm training Volcarona and it gains steady levels from Lv. 60-65 pokes in the sports domes, gonna try and elite four run soon here. I don't think Pass Powers wear off till after battles anyway.
Besides that, there's Hatching, Prize Money, encounter rates, and Bargaining (for shops) that can aid in a lot of common things the EV training and IV breeding.
Edit/update: My level 89 Volcarona was getting about 10,000 exp. from some of the pokemon used but the sports dome trainers, and it was easy to go to 2 or 3 trainers before the 3 minutes expired. Those later levels are killer with the exp. gained lowering, so the pass power is somewhat of a savior... I know a lot of people like to farm audinos, so I think I'm going to see if Encounter Power (up) increases those encounter spots as well as normal encounters, unless someone already knows... I also want to get a lv 1 pokemon with a priority move from another game, use false swipe to maybe get Cynthia's Garchomp to 1 hp then see how much exp it gains with trade bonus, lucky egg, and exp power... but that's just for kicks...