RB 2015 can use 64bit VSTis, and VSTs. So that is not a problem. I have track several projects entirely in RB. I seldom even use BiaB anymore. I find RB does 90% of what BiaB does in simply generating basic tracks for a song bed. I mix and process them right there. If i run into a situation where i can't get RB to do what i want i have Presonus' Studio one Pro where i can do what ever i want.

SIde note i was noodling around in Studio one last night, and trying different sampler sounds that come with the program. I was messing with a drum track that was basically a midi file i downloaded. I ran the file through EzDrummer, which is so easy in SD1, all one has to do is drag the VSTi onto the track, and a box pops up and asks "do you want to replace what ver synth it is using" Which in my case was their "Presence" sampler. Then i opened up EzDrummer and set it to multi output, and in the track inspector in SD1 their was a drop down arrow i opened it and it has check boxes for all the outputs of EZD. check each one and a track appears for each. Add effects to taste and mix down. Very cool deal.

HP Win 11 12 gig ram, Mac mini with 16 gig of ram, BiaB 2025, Realband, Reaper 7, Harrison Mixbus 9 32c , Melodyne 5 editor, Presonus Audiobox 1818VSL, Presonus control app.