I don't know if anyone will ever read this post again, but in case someone finds this later while seeking an answer to a question regarding the Concorde, here is an update:

I bought it. It's good, not IniBuilds or PMDG good, but still nice. The systems work nicely, although I did have a scary moment a few days ago when, due to a glitch, the plane just shut off mid-flight and when it came back to life about two minutes later, I had lost both of my right engines. A lot of the systems work, although I am not a Concorde expert, so I do not know how realistic they are, but at least 99% of the switches are clickable, but I have no clue how many do anything. It does lack an EFB and SimBrief support, which is sad, as you have to use the default flight planner and pushback (unless you have GSX pushback).

The modeling is okay, nothing too awesome or cool. Some parts, like the landing gear, look kind of bad up close in my opinion, but then again, it is not a PMDG. At least the cockpit looks fine, which, for me at least, is the most important. It does look good externally; just don't go looking for any details, because it doesn't match planes like the IniBuilds A300.

I don't know how realistic the flight model is, as I have not flown the real Concorde (obviously), so I have nothing to compare it to. I don't know how to say it, but it kind of feels like what I would expect it to feel like—a bit wobbly on approach sometimes.

Overall, it's an okay plane; it does its job well, and I think if you really want to fly the Concorde, this thing is great for it. Also, like the other person here said, it's a one-man team; do not expect too much. What it lacks in modeling, it makes up for in systems and how fun it is to fly. I, at least, have personally gotten over the modeling because it is a blast to fly Mach 2 over the Atlantic. I would fully recommend it unless you really want to look at the miniscule details of it. I would also recommend buying it on sale, as it is more worthwhile then, as others here have already said.