I'm considering the purchase of an AR-15, and it will be my first.  I'm looking for some feedback on which type of upper is most practical.

I'm leaning toward an A2 upper with a reflex sight mounted with a channel for the iron sights.  This is appealing to be because it's affordable, the irons can't be misplaced/lost, and I have access to the irons and the optical sight seperately (without cowitness) in case the optic is destroyed (can't cowitness if the sight is crushed/shot/fogged or  otherwise FUBAR).

The flat top uppers are certainly appealing, but I'm turned off by the price of back up irons and quality mounts.

Am I right on, or are carry handle mounts crap?  Are quality flat top components really as expensive as they seem?  Educate me.

I only use an Aimpoint for dark or low light shooting and the A2 handle is way stronger.Although if I went flat top Id get a fold down front and rear.Depends on tastes and what you want to be able to do.If your gonna use other optics beside a red dot go full flat top.If not the A2 will do.I have an ARMSON sight on the way it comes with an integral mount for the handle.For my aimpoint I use a $40 ARMS carry handle mount and the sight on a QD mount.I can also see my irons through the mount channel.

Flat top. Lot's more versatile and you'll end up getting one anyway.

Quoted: Flat top. Lot's more versatile and you'll end up getting one anyway.

BINGO!!!  I was in the same boat and I chose the A2...  Just recently sold and now have a CMT flat-top.  Don't get me wrong, I had a sweet A2 setup with an EOTech on an ARMS #2 carry handle mount but eventually I realized that I had made a mistake.  I swallowed my pill and bought the A3 upper and couldn't be happier.  You are correct that the A3 is going to cost more but the reason is because it trly is a "better" system.  Way more versitle and as stated above, you will get one eventually anyway.  Mounting optics way up in the sky on an A2 gets old and it gets old real quick.  To eah their own, however.

If you start out with an A2 you'll end up wanting a flattop eventually.  Go flattop with removable carry handle.

I got a A2 fixed upper receiver sitting in a box in the basement...Ask me why.....

I bought an A2 and after a while of being annoyed about mounting optics I had the A2 switched out for a flattop.  A2's are nice if you are never going to mount a scope/red dot but it really doesn't make sense when you can get a flat top that has a carry handle.  The Flat top is so much more versitile and the better way to go.

Quoted:
If you start out with an A2 you'll end up wanting a flattop eventually.  Go flattop with removable carry handle.[/quote

I started out with an A2 and still own one. I don't want a flattop.
Having said that, if you want to mount optics, flattop is the way to go.