I've plugged holes in tires before with nary a problem. My truck tire with 80psi tires had a plug for about 2 years before it was replaced due to tread wear. Never lost any more air than the other 3 tires (normal atmospheric pressure loss). My wife's car has had a plug for about 4 years without a problem.
On a vehicle that has a TPMS system, I'm not worried about a plug. Like other's said, a failure of a plug is likely going to result in a slow leak. TPMS will show that.
Some of y'all make me laugh... yes a plugged tire could have a catastrophic failure... but a non plugged tire could have one too. If plugs were so inherently dangerous, they wouldn't be able to sell them anymore. If we are so scared about the minimal risk of danger, none of us would ever leave the security of our parent's basements...