We've stopped selling most Taurus automatics at my shop, and we're taking a hard look at their revolvers.
I've seen several with bad timing out of the box. One specimen had a broken firing pin. They DO test-fire these, right?
In the last year, I've seen three broken forcing cones. Twice, I've seen an odd defect related to the manner in which the yoke screw attaches to the left side of the frame, and it leads to the trigger disconnecting. None of these guns had more than a few hundred rounds through them. Many times, these problems occur straight out of the box.
Average warranty service time for Taurus hovers at ~8-12 weeks. I'd estimate the failure rate at around 15-20%.
Smiths have problems, too, but not on this level. The most common problem I see is light primer strikes from the strain screw working itself out with time. That's easily fixed on the spot. I've seen one barrel that was screwed in off-center, one 340 with a cracked top strap (owner fed it a steady diet of .357-brave man!), and a few worn parts here and there.
Except for the crooked barrel and broken 340, all of these guns had a long life before any problems happened. The guns that have returned to S&W are generally back in 7-10 days, and by all accounts (I've personally dealt with them), their customer service is excellent.
Failure percentage for S&W revolvers would fall in the low single-digits.
Now, I've seen some Taurii that have lived long, problem-free lives, but it seems that you're taking a real gamble when buying one. All makers have a lemon now and then, but Taurus manufacturing seems very hit-or-miss (especially when factoring in their automatics).