I have 2 working V1's on 6S with internal BEC, but popped my first V2 on 6S 10 seconds after first initialization.
I refuse to use an external BEC with the MMM!!!! Really - what's the point?
If I want to use and external BEC, and a fan mod, and a cap mod - well.....

- I'll do what I did after my V2 popped...... Go back to my modded MM with fan and CCBEC.
If I buy a 6S ESC with an internal BEC I am going to use it just that way. I appreciate the time (and money) that CC has had to eat with the problem they are having and I know that eventually the product will be rock solid just the the MM is now.
Once the V3 comes out and has been proved to be a solid controller I am going to send in my popped V2 for replacement and then when I get that back I will send in my V1 controllers 1 at a time as well for an upgrade.
In the meantime I have picked up a MGM E-series 8025 6S sBEC controller that just came in the mail today - I hope to get it soldered and programmed to run this weekend. We'll see how this one goes.