The Burris is fantastic. The glass on it is great.
Scope:
If you browse around forums (non-AR ones) all the bigbore guys love Burris because it outlasts the rest. These are guys with 45/70's and bigger recoiling guns.
The ballistic plex is by far the best feature to come on a reasonably (see affordable) priced scope in a long time. It will let you compensate for drop out to 500 yards, in 100 yard increments with .223. The thing is, the ballistic plex is sort of a "average" of the most common trajectories. So some are dead on, others may be 1" high, or 1" low. If your goal is to shoot microscopic groups...then I guess a standard reticle with target turrets would be best, since then you can dial in your zero (if that matters to you). I like the no thinking approach. Just place the 300 yard mark on the target that's 300 yards away, and you're done (except for windage of course).
Best part is, the drop compensator will work on virtually any caliber.
For me, 1" high or low isn't a big deal out to 400 yards. That is still a center of mass shot on a human sized target. For different velocity and weights of .223 or any load with the ballistic plex, it is really easy to use a ballistics calculator to figure how high or low you are on certain marks. You can also reconfigure the drop compensator on different magnifications if you choose. If certain marks (say the 300 yard one) are 2" high or low..and that is too much off for you, you can always sight in the 100 yard mark 1/4" high or low depending on what you're trying to do, and the rest of the drop compensating marks will all index perfectly at their ranges for a given load. It is very versitile and easy to use. At first I was kind of overwhelmed by a number of questions about how that would all work out. But it is really cake and I am glad I got one.
This scope comes with a spotter. No, it isn't a 45-60x top dollar spotting scope. However, it is clear, crisp and does the job. At 24x, you can see holes at 200 yards. Beyond that, I like to use shoot-n-see targets no matter what type of spotter I am using that day. I've found anything over 24x to be impractical since the mirage becomes a big problem. Depends where you shoot I guess. Also, what kind of targets you use. As you probably notice, I am not a big fan of massive magnification. I don't believe that military snipers/marksmen use more than 10x. ACOGs are 4x.
I've noticed that the Burris doesn't get a lot of fans on this site, but in other places it does. To me, it is like a poor-man's ACOG in the sense that you've got a VERY decent drop compensating reticle on a scope with great glass, and is built like a tank and the bigbore nutz rave about their durability. I can't brag about the recoil toughness of mine, since a .223 doesn't kick at all. DO NOT jump on me, I didn't say it was suitable to fill the role of an ACOG. Just that it will compensate drop just as well.
If it didn't have the ballistic plex, then it wouldn't be as enticing. That is a great feature that is worth the money, but that is just my opinion. Your personal use of the rifle and for what kind of shooting is critical. If you are out to make the smallest groups possible, get a high magnification mil dot. If you want to have a simple drop comped scope that can nail a human chest out to 500 easy, ballistic plex serves that purpose WELL.