Since I'm currently considering buying one of these, I'll chime in. I definitely dislike the idea of a magazine disconnect. I think it is one of those completely stupid safety features that contributes nothing to real safety. The thumb safety is something I can either live with or without. I understand some people's adverse reaction to having a safety on a carry weapon - primarily because of the chance it will get accidentally engaged when they are used to carrying with it disengaged. It seems that some pistols are more prone to the safety accidentally engaging while holstering than others.
All that being said, I would probably lean towards the Pro version simply because of the lack of the magazine disconnect.