I missed what the OP is towing with, if it was mentioned. If it's a smaller tow vehicle, like an SUV, then the 7 footer is preferable, IMO, b/c there's less frontal area - less area sticking out on either side of the tow vehicle while dragging it down the road. We tow our Aliner with a Pathfinder, which is a good match. The Pathfinder is only rated for an 80 sq. ft. frontal area, which would have us picking a 7 foot wide TT over an 8 ft. wide one, for sure if we upgrade. A friend of ours tows a Casita with a Nissan X-Terra, and they like the match up. Someone else on this forum tows an Escape (like a Casita) with a Rav 4, I think.
If the OP is towing with a truck (150 or larger), then an 8 footer would be fine.
