What DNS said...
I tried it with an xSight I, didn't care for it and it's kind of redundant to look through a sight for a laser pointer, when the cross-hair from the scope is already there. Where I have seen some people use it is in conjunction with a good helmet mounted NV monocular like a PVS-14. The cost to buy one of those is about what an entry thermal is now.
M&P-10+AAC Cyclone - Kel-Tec RFB+Griffin Sportsman Ultra Light 300
ATN OTS 336-70mm 60hz Thermal Monocular
ATN NVM14 NV Monocular