For a nice jazz bass, check out Coyote Forte. I agree with the original poster that the RealBass often leads to undesired lines. My biggest gripe is with the slow ballads. Even using the 'A' pattern, the passage gets quite busy. My solution was to find a couple of midi styles I like and use Forte for the bass. No complaints.

PG sells Forte with a 30 day return policy. If you have an good external synth, even better.

R