I have a LMT on a rifle with an Aimpoint. I like the sight, but agree with Grant regarding the LaRue BUIS. I have a LaRue on another rifle, which also has an Aimpoint. Comparing the two sights on nearly identical rifles, I offer the following:
-LaRue is lighter than the LMT
-LaRue is smaller than the LMT
-LaRue has an adjustable (yes, adjustable) throw lever. LMT uses a know. I much prefer the throw lever and believe it to be more secure (i.e. less chance of shooting loose) than the knob/screw.
-LaRue has a wideraperture channel, making it easier to see more FOV when focusing on the Aimpoint dot.
- LMT has elevation adjustment. I actually view this as a negative. Once my irons are zeroed, I NEVER adjust the elevation. Plus, I adjust the front sight pin to zero the elevation, not the rear sight. Therefore, the elevation adjustment on the rear sight is not something I need. The elevation dial is just something that could accidentally be changed and it adds to the sight's weight and size. YMMV.
-LaRue is CHEAPER.
What works for me may not be the best thing for you. I do like the LMT and have no plans to get rid of it. However, I'd never buy another one.
Hope this helps.