4.3.1 bb 5.16.02!!
As read from severals of pages, muscle nerd posted on twitter for those at 5.14, 5.15, 5.16 I really don't see an unlock coming. Rather, it'll be: update to 6.15 then downgrade to 5.13 . My 4.3 is on 5.16, what is your opinion on this? Should I just wait (no idea how long), or update to downgrade? Is it risky??
It's your personal decision. There is no public way to "downgrade" from 6.15 again.
Best option is to try and get an official unlock (via the carrier the phone was originally locked to).
If you don't mind the risk of GPS problems and can generate custom IPSW (to allow error free restore in the future), update to 6.15 and use latest ultrasn0w to unlock.