I read many brand forums daily. I will say as a brand forum GD is the best. Much more owner input. Most minor issues can be resolved on the owners forum. With that being said I find GD products to be no better or worse than any other. The issues with the Imagine line that I don't like are the OSB and MDF used for cabinet and in other areas. Low payload in many models. Paper thin cargo doors.
The floor plans are some of the most unique out there. Larger tanks as well.
The booth seating is terrible. I only weigh 150 lbs and sitting in a booth after one minute my rear is on the foam support. Most all the interior appointments are on the lower end.
But you're not paying much for one so it's all relevant.
With that being said if my son ever wants to upgrade I'd recommend an Imagine. They have some drawbacks but seem to hold up well during normal use.