I've tried an LED upgrade for my 2xAA mini-mag and hadn't been too impressed with the performance, so I've been leary of LEDs for Mag lights until I bought a new 3xD LED mag light. It vastly outperformed my 20 yr old 3xD mag light. So, I bought this kit. Wow. It works far better than the original bulb.

LED's do wonders for weak batteries providing bright white light till the end. But it comes at the expense of not being able to focus the beam in my mini-mag lite (2AA size). My 3D size maglite w/LED does allow focusing although the light seems weaker vs standard bulb when not in a tight focus.
Pros-brighter white light, even with nearly exhausted batteries. Longer battery life.
Cons-lack of ability to focus.
I regard the LED's as an overall improvement, although a bit pricey.

This was a quick and easy upgrade to my current collection of Maglights. The LED is much brighter and more focused then the old bulbs. I am wait to see how long the batteries last.

This upgrade LED bulb replaces the original and it sure works nice. The light is white now and much brighter than the original.

These upgrades LED bulbs are outstanding and makes the flashlight function much better than it was new.

This module turns your 3 cell maglite into a much better flashlight.
The upgrade module seems brighter than incandescent bulbs, even halogen bulbs, and throws a brilliant white beam.

The batteries last more than four times longer than with the original incandescent lamp. The beam is still focusable via the rotating maglite head as before the upgrade.
This module will probably outlast your flashlight as it is rated for 50,000 hours of continuous use. Another thing, it will not easily break with shock like a fragile glass bulb.

To sum it all up; greater reliability, more light, longer battery life, no problems.
By the way, shop for a good price. These same modules go as low as 12 dollars and as high as 30. Cheers.