If you're used to standard Minimag, the Minimag 2AA LED makes a night and day difference. It's important you get the factory LED Minimag, because the common Nite-Ize drop in does not even compare.
The cost is around $24, which includes belt holster and Duracell alkaline batteries. You can get it at most dept stores and you get a little over three hours with a set of alkaline batts. It doesn't have a string attaching hole in the end and the overall length is slightly longer. The operation is exactly the same as your old Minimag. Just like every other Mag products, it comes with a lifetime factory warranty.
Fenix L2D-CE sets you back about $60 shipped. It has four level dimming and two blinking modes, but I find it is something you'll need to read the manual to figure out and if you're going to lend it to someone, you may have to give him a lesson.
It comes with a lifetime warranty through the manufacturer, Fenix, China. Local warranty is completely up to the dealer you purchase from. (Which could be anything from a few months to lifetime of the .com dealer)
Fenix L2D/L1D-CE instructions:
"[T]o use "Turbo" mode (Max/Strobe), simply make sure the head is tight against the body. To switch betwen Max and Strobe, partially press the tail switch in until the light blinks off. When you release the switch the light will be in the next mode. To use "General" mode (Low/Medium/High/SOS), make sure the head is not tight against the body tube - loosen it 1/2 turn from tight - then half-press the switch as described earlier to switch between modes. To quickly put the light in Max mode, just tighten the head again while keeping the light on. Dimming is achieved with constant current regulation circuit which means there is no flickering of the LED in dim modes. If the light is turned off for 2 seconds or more, the modes reset, starting from the beginning again the next time you turn the light on." (
http://www.flashlightreviews.com/reviews/fenix_l1dce-l2dce.htm)