You either like flippers or you don't, just like you prefer tip-up or tip-down. It doesn't really matter & it's good that you have that choice with Hinderers. In reference to Art_Vandeley's comment about his 3" flipper, I think the bigger your hands (XXL gloves are tight on my hands), the more you'll probably prefer a non-fliper on the 3" model. The flipper tends to push your finger back, not allowing you to use quite as much of the handle as you would if it's not there. Needless to say, my 3" XM-18 is a non-flipper for that reason.
As far the blade opening easily/quickly, I think they both work very well.