it really depends upon the fish you put the betta with and your bettas demeanor - whether hes laid back or would prefer to chase everyone around the tank. Also, no so much the current but the power of the suction on your filter, mine usually had issues getting stuck to the intake because of all their long fins.
In the long run I think its really up to you, I kept a betta in my comm. tank for years. I just didn't have one in my last one because it was an aggressive (barbs, aussies, gouramis, etc) tank.
Good luck =]

per aspera ad astra: Through rough ways to the stars...