When I started brewing about two years ago, I did a few extract batches and then went straight to BIAB and all grain. I never even considered a 2 or 3 vessle systems and have made many great brews (in my and my neighbors opinions). However, I am now looking to go from gas fired BIAB to electric BIAB and was wondering if I should consider going 3 vessel HERMS or RIMS. I LOVE the simplicity of BIAB but almost all of my parts can be used in a 3 vessel system. What am I missing out on? Why do so many people go 3 vessel?