What are the conciderations when choosing a Holographic/reflex sight over a tube type like an Aimpoint micro t-2?

Joe

Generally speaking mini reflex red dots, like Leupold DeltaPoint, are smaller, lighter, and have no knobs, dials, switches, battery tubes or other obstructions to peripheral view around the optic.  

In the case of the DP Pro, the window or viewing screen is much larger than the Aimpoint's tiny round 20mm lens.  Mini reflex sights have no "tunnel effect" .  You look at the screen, like a video monitor, rather than through it.

The down side is that the space between the emitter diode and the screen is open to the elements and can get covered with water or mud, keeping the dot from reaching the screen.
This is easily cleared, typically by simply shaking it off, but bothers some users. Covers are available for some models, like the Burris Fastfire 3, but I've not seen one yet for the DP Pro.

Battery life depends on the optic.  In the case of the DP Pro, which is motion activated, it will likely be comparable to Aimpoint - many years.

Agree...I was amazed at how much wider my Razor Reflex FOV compare to AP Pro/Sparc 2, better peripheral too, weight next to nothing. One down size was that the up/down button was a pain to use.

Thanks Guys.