I like that you asked which you prefer, and not which is better. Since you really can't go wrong with either, and it truly is all about preference.
For me? My first "real" knife purchas came down between the PM2 and 940. I don't think I've researched a knife purchase more since. I wound up choosing the Benchmade, mainly because of the size and lock.
Of course, once you start researching something that much, there is a strong chance you can fall down the rabbit hole. And down I fell. A month or 2 afterwards I bought the PM2.
Many knives later, I still have the 940 and it still gets some pocket time. One day I may give the lefty PM2 a shot, but I've pretty much moved on from that price bracket.