I have one and rather like it. It's not my go-to device by any means, I bought it more as back up and to have a rechargeable mod.
It does have two modes--3.3 volt moderated (like a standard eGo) and unregulated so it follows the battery voltage, or 4.2 down to 3.2 when fully drained. Aside from the lock, and the pretty standard cut off time, I don't know if it has any other safety features.
It's definitely not for you if you like a smaller mod. It's quite thick and heavy, although not especially long.