Heh, I personally would go with the Arc AAA-P, but Ima newbie flashaholic.
I currently own both the Fenix L0P and the Arc AAA-P and while the "pitch black" shots of the fenix clearly blow the Arc AAA-P away in tint, real life wise, I really don't find much of a difference. You can see the blue on the Arc, but truthfully, unless you shine it against a white wall, the beam color (brownish) is rather unnoticable. I heard Peter recently changed the 5mm Leds to a whiter one (which is the one I got), and really, the blue isn't even close to the beamshots on the forums, its a more, whiteish blue rather than angry blue. I thought I would regret my Arc AAA-P decision after I got the L0P, but I still find the Arc AAA-P residing on my keychain (L0P now gifted to a friend).
Same thing goes with overall output. The difference you see in them is marginal (again, if your not walking in pitch dark, and if you are in pitch dark, you need another flashlight). Frankly, what really sold me was the runtime on the Arc AAA. Place them side by side for a while, and you'll notice the Fenix gets dim, after about 45 min- 1 hr, the Arc already outshines it (and the fenix dies shortly after). I don't have that many rechargable batteries hanging around either...
I can't say anything about the Gerber or the L1P becuase currently I only have 3 flashlights, Dorcy 1W CR123, Arc AAA-P, and L0P. I would probably go with either the Peak equivilent of the Arc AAA or the Arc itself. If your going to go for the 3 LED Peak tho, I'd just go with the L0P. Pricewise, the L0P and the Arc are about the same shipped. Its just runtime vs tint/brightness. While tint is truly superior to the Arc, brightness is not as noticable as you might hope. It is significantly brighter, but there isnt the "WOW, sacrificing 4/5ths of the runtime was SO WORTH IT" feeling if you compare the two. However, I think MillerMods is working on a 3-stage for the L0P? It'd be around 80 dollars but worth looking into.