There are definitely known issues with using VGC. They are bad for places like gas stations and restaurants where they put a hold on the card that is higher than the actual amount that is charged. Either they may decline or the hold will take over a week to fall off. I've also had issues where random retailers (a local garden store where we buy our Christmas tree, a local theater group) just can't get the VGC to go through. It can also be annoying to finish them off because a lot of places have to charge the exact amount to get them to zero. Grocery Stores generally don't have that issue, so I bring all of my cards that need finishing to my weekly shopping trip, but I can see having them in Disney where you're dealing with a bunch of partial balances being super annoying.
That said, I use them a lot because I will buy them to hit bonus on a CIC to get the full 5% office supply store on top of hitting the bonus. I've got a ton right now as I just bonused a card during their last offering. If you know how to use them, I personally find it worth the hassle to get the additional percent back. But, I'm willing to tolerate probably more hassle than most, knowing that I get $10 in UR for each $200 VGC I have to deal with.