I cant speak to the 140, as I don't own one. But Taurus can be a "mixed bag" of successes and failures, in gun design.
I own 2 Taurus handguns. One is a wheel-gun... a long-barreled Tracker series revolver, in .22 long rifle, that is an absolute joy to shoot, and is an insanely-accurate tack driver. I've never had a problem with it, and really really enjoy shooting it.
On the other hand...
I've had a Taurus PT145 Millennium taking up space in my safe for several years now. Honestly, I've put less than 200 rounds through it. It seemed like a very comfortable gun to shoot at the range, and I had read some "glowing reviews" in the magazines. I had high hopes. Then, on the second trip out, it broke.
You see, the PT series uses PLASTIC tabs inside the gun, to engage the slots on the magazine that hold the magazine in the gun. Be kid-glove gentle with your mag changes, each time / every time, and you'll likely never have a problem. But slap just one mag in with any gusto (as when adrenaline is flowing), or perform just one hearty "tap-rack" stoppage drill when shooting "on the clock", and the magazine will shear those plastic tabs right off the inside of the gun.
The result is a mag that will stay in the gun long enough to chamber the first round, but the recoil of the first shot will shake the rest of the loaded mag right out of the gun, sending it right to the floor (or the ground). Subsequent magazines will not stay in the gun at all, since the tabs that hold it in will have been sheared off, and will have fallen out of the gun when the mag that sheared them, fell out.
I sent my gun back to Taurus, and they repaired it at no cost, without question. But that gun has stayed un-fired in my safe, ever since. I'd NEVER bet my life on it.
I cut my teeth on combat-proven, all-steel .45 cal 1911's, in the service. Today, I shoot IDPA, train frequently, and I carry for self defense. I'm constantly doing mag-changes with the guns I shoot regularly (mainly 1911's and XD's), and I've never encountered a problem with these guns. Spend a weekend at any training facility where you'll be shooting 500 or more rounds per day (TDI, Gunsite, LFI, John Farnam, etc.), and you'll know in the first half hour, exactly what I'm talking about.
If you intend to rely on a gun (any gun) for self defense, be sure to take it to the range and seriously beat up on it. Run at least 600 hard rounds through it in a single weekend, as if your life depended on it. If your gun ends up broken, then decide at that point whether you'd be willing to bet your life on it.
There are many other guns on the market, from a multitude of manufacturers, that use good quality, forged / machined steel parts everywhere that can encounter stress, shock, or impact of any kind, and that save the plastics and polymers for where they can be used without jeopardizing combat-ready reliability. Guns that use plastics for parts that are critical to the safe and reliable operation of the gun WHEN A LIFE DEPENDS ON IT, should be avoided.