We have camped at this park (formerly Seaport R/V Resort), for four straight seasons and look forward to returning each year. Although there have been management issues in the past, this seems to be resolved and the staff and management are super friendly and accommodating. The campsites are spacious and the restrooms are as clean as any we've seen.
Seasonal campers are quite common in CT parks and this isn't a bad thing. The seasonal folks in our experience are friendly and eager to offer insider tips on the locale. The S.O. Mystic park has its share of seasonal, but for the most part they aren't living full time in their R/Vs, but using them as weekend escapes. Their units appear to be well maintained and road-ready and they have to be, as owners are required to vacate their sites at end of season.
To sum it up - top notch!