Yep there sure is! Due to "old eyes" (had the same two all my life
) - I use scopes on most of my AR's.
I have a couple of A2's but the last 20 or so that I've built have been A3's.
Like mjkeat pointed out you can set your cheek weld perfect for your head and its easy to do a rock solid mount on an A3.
Now this is just what I do, not saying its right for you, but I use a standard FSB on all my A3 uppers. I also use a removable rear sight, (Bug-Out Handle). They are only around 50 bucks, not much $$.
My scopes are mounted with a quick release riser or rings. Before sighting in the scope, I sight in the iron sights, pop them off, now I have back-up irons for each rifle. Sight in the scope, then I can switch back and forth between A2 type sights and a scope with no loss of zero on either.
JonM is telling it true, its a real sob trying to get a good solid mount on an A2.
The AR in the pic is the one I carry in my vehicle. Its an A3 with a removable bug-out handle, if you look close you can see the two bolt knobs that hold it on. I have a couple with just a removable fold down rear sight, but I like the full handle better, guess its all in what you are more comfortable with.
Good luck with your project & welcome to the forum, Ken