There was on old thread a few months ago where Sig exchange the OP's Gen 1 model with one of these new models under warranty, but I don't recall seeing any feedback from him on it. I am actually sending in my Gen 1 tango 4 this week for warranty work and I'm curious to see if it comes back as a Gen 2. If I do get upgraded, I'll let you know. The new model's turrets appear to be similar to the way it's done on the Tango 6, hopefully they'll be an improvement because the turrets are my least favorite aspect of my Gen 1
They eliminated the locking turrets, and mine was very mushy on the clicks.
I traded mine for a gen 1 specifically for the turrets.
Unless I missed something, there was not a single mention of locking turrets in the instructions it came with, and I couldn't find anything from SIG about it, and they damn sure didn't lock anywhere out of the box.