When I got a flat around a month or so ago, I went through the same thought process. 2 things helped me make a final decision. First thing I considered was the cost.
1) $100 bucks to plug a tire when all is said and done, and all the doubt to go along with it.
2) $200 bucksfor a brand new tire, taking the rim into a shop, and letting them re/re a new one...and complete piece of mind.
Also worth considering is the power of your bike. What many don't realize is the heat that is built up as your speed increases. As an example, one study I read showed that using a starting point of 100 km/hr, one could expect to see a 60 deg increase in temp by 120 km/hr!
What would it be if you reached speeds of 150+ km/hr?
Long story short, my piece of mind was worth the additional cost of opting for new rubber and avoiding a plug.