RBBS, Colletts, from my exp not very different in attitude, neither would be more ideal then the other as a first venomous snake. I haven't had any drama's with any of the ones I have kept over the years, most have been well behaved and the few that haven't have never been too bad that I was worried. Their venoms aren't much different to one another, I think they are placed one after the other on the most potent venom chart, correct me if I am wrong. Both pretty snakes, I prefer the colletts more but still I like snakes that vary heaps in colour and pattern and colletts and rbbs aren't examples of this. You can still have some outstanding examples (more so with colletts than rbbs) but the differences aren't as extreme as other species.