Laser modules on 12 o'clock rail
 

I'm wondering what kind of obstruction they make when used in this position with optics mounted.

I found this picture showing the (quite clear) sight picture through an EOTech with a PEQ-2 clamped ahead of it on an M4 and I'm wondering if the view is comparable when other optics (e.g., ACOG, Aimpoint, etc.) are used instead of an EOTech.

http://i294.photobucket.com/albums/m...4A1EOTech4.jpg