I compete with (IDPA) and carry a 4" barrel 629 regularly. I often use an IWB kydex holster from Hoffners if I want to be really concealed, but it doesn't print all that noticably with just a pull-over shirt over it, even with an OWB holster. (I'm 6'-1", 205 lbs) Though, what I consider "acceptable" printing might not be the same as what you do. I'm in PA and there is no requirement not to print, or to stay concealed at all, for that matter.
My competition loads are 200 gr. Lead Round Nose at about 825 fps. Which is exactly the same weight and velocity I load .45 ACP to. Very controllable. I can get split times in the 0.28 sec. range (as opposed to sub-0.20s with the 1911) -- I'm more slowed by the long, heavier trigger than recoil.
My social and light woods loads are kind of a .44 Spc. +P. 200 gr. Hornady XTPs at 1250 fps. They're in a .44 Spc. case, but are more of a light .44 Mag load.
I do keep some real .44 Mag rounds on hand (300 gr. at 1200 fps), but don't use them for either comp or carry 99% of the time. I just don't need that kind of power unless I'm hunting or hiking pretty far off the beaten path and really think I might need such oomph to annoy a bear.
I have, on occasion, shot the magnums in club competitions and, with the adrenaline flowing after the buzzer goes off, it's just not that big a deal. Other shooters watching say there's a lot more noise and blast, but if your technique is sound it won't throw you off all that much.
(I do chrono my loads, so can say with certainty what velocities I'm getting from my gun.)
Having said all that in defense of the .44 as a sidearm, I usually don't carry it in purely social situations as I find a 1911 (and the reloads for it, especially) to be a little more comfortable to carry and a little more easily concealed. The autoloader and mags just ride more flat against my body than the wheelgun and speedloaders.
On to the question of penetration: Even the mild 200gr/1250fps load is going to penetrate quite a bit. Certainly more than a factory .40 or 9mm or .45ACP.
"Overpenetration" is ALWAYS a factor with ANY round you shoot in ANY situation where something beyond your target could be hurt or killed. There's no guarantee that even some powder-puff 9mm is not going to exit an attacker's body and go on to do damage to someone else. Further, if you've done much shooting -- certainly if you've done any practical competition -- you'll appreciate that not every round you fire is guaranteed to even hit your intended target. So the problem of "overpenetration" by a heavy round is greatly overshadowed by the far greater risk of damage from every round that passes by your target and goes on to hit something else -- regardless of what caliber it is!
Having said that, yes, there is a marginally greater risk of damage (from bullets that hit the target and pass on through and those that don't even hit the target first) when those rounds are faster and heavier than some other choice. Point is, you have to account for what your bullets will do to whatever is behind your target every time you shoot in every situation from the range to the battlefield and with every cartridge you shoot, from .22 CB shorts to a 4-bore elephant gun.
I won't say that I don't worry about overpenetration with warmer .44 cal loads. I will say that I don't worry about such "collateral damage" more with them than I do with my .45 or any other round I choose to shoot.
SO, if you want to carry a .44, find a round that you can handle (remember, .44 Russians also work!) and practice a lot. Then remember to always shoot in a responsible manner, regardless of what you're shooting.
-Sam