Before I begin to try and answer your questions, I would first recommend you get some formal training with a carbine. It seems like a big investment; but it will do a great deal to improve your skills with a rifle and more importantly, it will give you the background you need to answer some of the questions you are asking yourself. Many of these questions cannot be answered by other people because they hinge heavily on personal preference and individual factors that only you know. A training course is not only a great place to gain knowledge, it is a chance to test more gear (your classmates, the trainer's, etc.) in a few days than most people will even get to touch in a year.
Bartholmew, I know I have heard a lot of complaints about it, but what would you think of Leupold CQ/T compared to Trijicon ACOG?
Depends on which of the many types of ACOG you are comparing it to. If you are comparing it to the TA01 or TA31 4x32 ACOGs, then the CQT will be faster close-in at 1x and nowhere near as good as the ACOG at 3x. There are several threads on this exact subject if you search the Rifle Country forum.
Do you think ACOG 3x is better for quickly picking up targets than CQ/T? Many people I hear complain about the CQ/T because it is bulky and such. Some say it is slow in acquisiton. I thought it may be desirable by the fact that it has variable magnification and a laser sight.
The CQT has an illuminated reticle, not a laser sight. The CQT is not a reflex-style sight and is dependent on good cheek weld and eye position like any other magnified sight. At 1x, it will be fast; but at 3x it has a short eye relief, small exit pupil and a very little tolerance for less than exact cheek weld.
Did you look at either of the links I referenced earlier? Those links can better show you two important things you need to understand:
1. The tenths of a second differences we are talking in speed on close (15yds) targets with reflex sights, variables, and fixed magnification ACOGs.
2. Why magnification can be important to acquiring a target even if it doesn't help your speed
What is more imporant? This is very difficult question for me. I could say it is acquiring a target at close range. But if two BG's are attacking me: One at 50 yards and simultaneously another at 400 yards, I can say both would be equally imporatnt to me.
Imagine the various
realistic scenarios for you being attacked and decide what range is more likely. The military has determined that something like 98% of all infantry combat takes place under 300yds and 90% of it under 100yds. The military likely has a much less restrictive rules of engagement than you will have as well. Look at the sightlines on areas you plan to defend, what kinds of ranges are even possible?
The problem I hear with Trijicon's is lack of eye relief. At 3x or 4x, I can see that a close target would be hard to acquire, because of small FOV.
Again, depends on the model. The 4x32 ACOGs have about 1.4" of eye relief; but they also have an 8mm exit pupil that allows for some flexibility in head position. The 3x30 and 3.5x35 ACOGs have about 2.4" of eye relief and 10mm exit pupils. This means more flexibility for shooting while moving or shooting from odd positions.
Let me give an example, if I have Scope X, with a 5mm exit pupil and 2" of eye relief, my head has to be in a fairly exact position in order to even see the reticle. To the extent it makes me use the same cheek weld, this is good; but it also means if I shoulder the rifle sloppy or recoil/movement bounces the sight around that I might lose the sight picture entirely. The longer eye relief combined with a big exit pupil means better lowlight performance and it also means that even if I miss my cheek weld, I can still see the reticle. The point of impact will change with the different cheek weld; but at close range I can be accurate enough and still quick.
However, target acquisition can be a problem at close ranges with the small field of view. One problem I have with my 3.5x35 ACOG (TA11) is that when shooting at brown IPSC targets while moving, I will occasionally "bounce" over to a different target and not realize it due to the fact that all brown targets look the same and the field of view issue.
Also, without a variable magnifier, wouldn't be fixed at a certain magnification bea disadvantage for targets that are moving in and out of distances. Does the Trijicon Bullet Drop Compensators make up for the lack of magnification?
The BDC is only useful past 300m for the most part. How likely is it you'll be shooting defensively past 300m? Maybe you should tell me more about the type of scenarios you envision happening?
I don't really get why an ACOG is so great if it is always stuck at one magnification, whereas a scope can magnify according to the proper position of the target?
Well, the ACOG is very durable. It has enough magnification to make target acquisition and accuracy at realistic combat ranges better, while at the same time not having so much you can't use it closer.
The ACOG, like all general purpose optics, is a set of compromises. Since you haven't been very specific about how you plan to use it, it is difficult to offer an opinion on whether that set of compromises will work for your uses or whether something else would be more appropriate.
I know reflex sights seem to only be a replacement for iron sights, as they dont seem to reach farther than 100 yards, which is a disadvantage in a real battle situation.
I don't think you have a good understanding of what you are talking about and that is hindering your efforts to answer your questions. This is why I think formal instruction would be a great value for you (and just about anyone really).
FWIW, the reflex sights offer many advantages over irons. They do not require a consistent cheek weld. They only require sighting in a single plane. They are much faster on target.
A red-dot/reflex sight will easily reach beyond 100yds and you can make fast hits on silhouettes out to 300yds easily (and beyond that with practice). However, because these sights are unmagnified, you still have to see and acquire the target. On a range, not so hard; but even there, the dot will be large in proportion to the target and you may need a few tenths of a second more compared to a magnified optic. Off the range, the magnified optic may be necessary to even see the target in the first place plus the small speed advantage at distance. However as that distance closes, the magnification, field of view and necessity for a good cheek weld will slow down your times so that around 100yds the red-dot/reflex starts to win out more often.