stopping for a single night - rest area or rv park?

I'm a light sleeper, and sleep SOOO much better in an RV park. We've tried Flying J's, and invariably have the guy next to us who idles his diesel all night to stay warm, plus trucks coming and going all night... Walmarts are better/quieter, assuming the weather is nice enough to not need heat or cooling; but sometimes they attract folks who aren't the "RVing Crowd". And I like to support RV parks - quite often you can get a lower rate for electric-only sites.