Hi om, sorry for the delay for this the reply (and it's brevity) I had a lot of company over the weekend and barely had a moment to myself.
I like experimenting with sound design, and different ways you can work with audio using FX plugins and being able to manipulate their parameters to evolve and change over time. Sometime ago, I participated in another one of these "who needs Reaper?" threads and jotted down a list of 30 (IIRC) functions that I use in Reaper that you don't have in BiaB or RB. Unfortunately, I can't seem to display the actual text of my responses when I look in my comment history, (only the title of the threads) and I don't really have the time to go coming through everything.
Just 3 examples of how I want to use certain Reaper features with plugins on RTs (and sometimes in conjunction with MIDI). 1) Routing MIDI notes and automation to tracks with to trigger gestures. 2) Sending/sidechaining one RT to another RT or RD loaded with an instance of Transmutator to morph between them over time. 3) Sending a MIDI chord track similarly to a RT or RD drum track with an instance of Vocalsynth 2.
Some of my favorite features to use in Reaper have to do with using the Last Touched Parameter function to assign MIDI controller knobs or mod wheel to any effect or VST(i) parameter I please, and then assigning opening an envelope to modulate those parameters. Then you can record automation in realtime, and even record takes in the same way you can do with audio.
Next, I personally find the piano roll in RB near unusable, not to mention severely limited in functions/features. Also, the program is extremely slow, finicky, and prone to freezing every 5 seconds. Admittedly, my PC may be a bit long in the tooth, but Reaper still works lightening fast and smooth on it.
Again, if it works for you, then that's awesome. I'm sincerely not trying to throw shade in this program!