We are 30 amps and use a 50/30 adapter maybe 2 or 3 times a year. We use mostly Thousand Trails CGs all over the place and you often don't know what you're going to get until you're there.
Besides 30 amp receptacles in pedestals often being in pretty rough condition, low voltage is a common issue in the summer time. Plugging into a 50 amp receptacle typically should give you better voltage due to the heavier feeder cable to the pedestals. Once in a while you may have a choice of a site with 30 or 50 amps when signing in and choosing 50 amps is usually best.
50 amp pedestals can be scarce in CGs. Up until 2005, only 5% of a CG had to have 50 amps by the NEC and then it was changed to 20%. Some CGs may have voluntarily built above min. code like casinos and some gov't CGs, but the majority of CGs are older ones built to min. code. We've been to many CGs where if you want 50 amps, you have to go on a waiting list until a 50 amp site becomes available. It's usually the full-timers that snag them and weekenders are out of luck.
If you're 50 amps, inspect a 30 amp recept. carefully. If it's blackened, "crispy" looking and your shore power plug barely stays plugged in, look for a better pedestal if possible. Check voltage too. If you don't have a choice of a better site/pedestal, you may want to keep your loads to a minimum to reduce the risk of overheating at the pedestal.
A dogbone style adapter is preferable because if the pedestal to shore power connection overheats, a dogbone will transfer less heat to your valuable shore power cord and you may only have to replace the adapter. Always keep the plug blades on adapters and shore power cords clean with some emery cloth as needed because if dirty & pitted can contribute to a bad connection and overheating.
Extension cords and adapters are not required to be UL/CSA listed. It's a good idea to check an adapter to see if it's marked UL/CSA. If not, it could be cheap junk inside and increase the chance of overheating. Last time I looked, CW had nothing that was UL/CSA listed.
