I like AOs and flippers. The "fun" aspect of the fast opening and the thwack of a Kershaw Blur helped reignite my interest in pocket knives in general. Plus, its almost like being able to own an Auto, which is illegal in CA.
My current favorite is an AO with a flipper, a Needs Work. It is really convenient when holding the item to be cut in one hand to be able to open my knife with the other. I could always use a knife that can be opened with a wrist flip, too, but I kind of worry about losing my grip and sending it flying.
I'm not too worried about the torsion bar breaking. The frame or liner lock will still work or even the Axis lock on the new Benchmade AO. Most pocket knives use some sort of spring to lock the blade in some fashion, from lock backs to "Axis" locks. Like Phillip Dobson pointed out above, I'd be more worried about one of those springs breaking at an inopportune time. A broken torsion bar is an inconvenience that can be remedied with an e-mail to Kershaw customer service. A new one arrives in the mail in a few days.
I don't limit myself to just pocket knives with AO or flippers. I've got some very nice knives from Spyderco and Benchmade that I like. Gotta try the classics from the best companies making production knives these days. I've got a whole bunch of Kershaws that I love, too.
I've got an old Buck 110 from the 70s and an Alpha for my BOB. Some Gerber fixed blades from the 70s and wish I still had my Gerber and Puma lockbacks from that era.
Being tied to one brand or one style of knife is too limiting if you're going to be a knifenut. I've even got a 2009 Forum Traditional on order. You don't have to like every kind of knife out there, but you shouldn't be afraid to try something new (or traditional) every now and then.
BTW: Almost forgot a Ti/G-10 M4 Millie that's on order. And before that arrives I hope to have a ZT 0300. Titanium frame locks are going to lead me to ruination. Next I'll have to get a Sebenza to compare the others to.