Although the Bass RealTracks are good I personally never use a BIAB bass line. I always like to create my own as the RealTracks never quite play what I want them to play. They will have strange and inappropriate leaps or maybe a walking bass will be OK for a while and then suddenly jump to a wrong note. Sometimes the bass notes can sound out of tune to my ears too. I think the bass is such a crucial element of a song that it is best to create your own lines. This applies no matter what the style jazz, funky, country or pop the bass line is the glue with the drums to creating the correct groove. I use Spectrasonics Trilian or MODO bass but there are many excellent bass vst instruments to choose from.