The idea of an internal lock doesn't bother me. After all, SW's original lemon squeezer was a type of internal lock as is the 1911's grip safety. It's SW's implementation -- it is just plain ugly. There is also the (relatively rare) chance of a malfunction. The Taurus system is done better. It is fairly innocuous and I haven't heard reports of any malfunctions.
p.s. I like pre-locks better but I do own two SWs with the locks.