Here is a quick video of my MOE with a UTG 3x magnifier....have to say it is a great addition. It can be focused to ensure the red dot remains clears but it definitely pulls the target in close. I say go for it with a FTS mount so you can enjoy the best of both sight options with a quick flip to the right.
M&P 15-22 MOE FDE at OBX Gun Club New Years Eve 2011 - YouTube