The Surveyor's appear to have a more sloped front end, which may (I hope) contribute to better aerodynamics and better gas mileage . But I think that is also why the units with the front bedrooms have the wardrobes coming all of the way down, preventing a night stand under the wardrobe. The Surveyors also don't have a front window, which I really wanted.
The Surveyors also have ducted heat and air with an enclosed undercarriage, but I not sure about those items in other Forest River products.
They all appear to be well made units, so have fun shopping around and choose the floorplan that fits your needs.