I'm using a Samson flip up front mounted on a railed gas block.  I need help deciding between my two choices for the rear.  Both claim to have .50 MOA adjustment at 100 yds.  And they both sell for about $140

ARMS Pros
-true flip up type (spring loaded)
-has notch type sight for close quarters

ARMS Cons
-while low profile it's still taller than the Troy
-not sure it even has a 200-300m aperture (it has to right?)
-requires a taller front sight post


Troy Pros
-lower profile
-I have one on my M&P15T and I like it
-Seems more durable

Troy Cons
-A little more difficult to adjust windage
-On mine the action feels a little "Sticky"

What say all of you?

EDIT:  What do you guys think of the GG&G BUIS...I'm looking specifically at the MAD BUIS.

I don't think the ARMS requires a taller front post.
I have both and like them.

However the new MI SP is the sight I'll be using on future builds. Almost a cross between the two and cheaper.
It has the windage knob of the 40 and the profile of the Troy. As a bonus it's lower than either.

My brother has the MAD and has been happy with it.

Troy and don't look back.

Oh, I didn't know that ARMS didn't lock.  That's the deciding factor.  Well that and I just found the Troy of Cals Sporting Armory for $125.  I thinks that's what I'm gonna go for.

Troy

ARMS