Hi all. Interesting subject. When I was younger I worked for a large tire chain changing and replacing tires and have plugged and patched hundreds of tires. From what I have read here all have good points.
In my experience (such as it is) I have seen plugs develope both slow and fast leaks, and others that have popped or pulled out completely. But, by and large the VAST majority have held fast. The reasons for failure can be improper application, hole too large for the plug (I have double plugged personal tires before, but NEVER recommend it

), wrong type of injury ie: where site is a CUT instead of a puncture as can be the case with glass or metal banding etc.
I have also seen patches that were improperly applied fail as well. But this happens much more rarely than plug failure. Patches are much less likely to experience water infiltration than plugs just by the very nature of the application. Airtight is a better seal that watertight and unless it is a large injury, the self-sealing properties of the rubber will negate most possibilities of water getting between the bands.
All that being said, I have done both for personal applications. The AV will be my first truck, but I have had a some pretty decent hotrods as well daily drivers. For the everyday grocery getter I wouldn't hesitate to use a plug. Very little heavy duty use here. But in the case of a lot of highway driving where a blow out can be costly, hot rodding where a blow out can be deadly, or Off Road use where you can be a long way from anything and out the reach of AAA, I would not use a plug. IMHO, for anything resembling heavy duty use I would do no less than a patch and possibly the patch/plug combination.
Just my $.02
Happy AV'ing