From what I hear, The possible draw back is at close range, the bullet may be going to fast to perform as advertised.
Not necessarily true. Bullet performance is dependent on the bullet's design. Use a quick expanding bullet and you'll get more meat damage. Use a slower expanding bullet and you'll get more penetration and less meat damage.
Believe it or not, the 7mm mag's velocity with a 145 grain bullet is very similar to a .243 Win with a 100 grain bullet. I've chrono'd both of mine, and they're
really close.
In fact, with a more fragile bullet, I get
more meat damage on a deer with a .243 at close range than I do with my 7mm mag. Using similarly constructed Speer SPBT's (100 gr in .243, 145 gr in 7mm), I doubt most would be able to tell which I'd used. These aren't even high-dollar bullets, but they work extremely well for me in both cartridges.
I've shot several of our little coues whitetails (they top out at around 100 lbs dressed for a really big one) with the 7mm rem mag, and I've yet to ruin much mean on one. The closest was about 8 yards, another was about 15-20 yards, and the farthest was 472. The bullets all worked very well, with each of the deer dropping immediately upon impact. I've shot antelope, elk, bear, and bison with the same load and got very similar results.
So IMO the 7mm mag is a great choice for deer, just like any one of many other cartridges. Loaded right, there's a big bunch of choices out there; the 7mm mag just happens to be one that fits my style and preferences really well.
I've used it pretty heavily since about 1986, and in my present rifle since about 1990. I have no complaints about the cartridge at all.