I obliviously like the Sparc II price better. Is the battery something common? I already have a trl1 light and i think they are the same batteries as an Eotech. I have been known to overthink this stuff sometimes.
I have always been an iron sight guy. I had a cowitnessed red dot on the m4 I took to Afghanistan. I had problems zeroing, took it off and later shot expert for the first time that day. I have a weird love/hate relationship with dots.
Most branches of the U.S military run Aimpoint CCO's for their red dots. Its mostly spec ops guys who run Eotech ect unless a grunt feels the need to buy his/her own optic. So if you didn't like the Aimpoint on your M4 i recommend a Vortex Strike Eagle or any scope with a 1x power setting so you can still run it like a Red dot but still have the added magnification when you want it. If you shot expert with iron sights you won't have any issues hitting most targets at the ranged around here don't think anyone has a range that reaches past 300 yards in the metro area except maybe OKC Gun Club.