One thing I don't like about the Drifter is that it's not powder coated stock.That's a $1100+ extra.
Another thing is that the aluminum frame is not as strong as a steel frame. Welding weakens aluminum whereas steel doesn't lose strength when welded. It's also narrower than the GFC.
A 6'-1" person can easily sleep in the GFC + its wider. According to their respective online sites, Drifter 80"L sleeping platform vs. 90" for GFC.
IMO the Drifter just doesn't look as cool as the GFC.
Not as streamlined too therefor the MPG is more affected.
Once you start to add the options to the Drifter the price goes up fast. I bet the full size version will be easily north of 10k with a 5k deposit.
I like the GFC translucent roof. It has a very nice diffused light quality which is great, especially on cloudy PNW days. And you can walk on it but it would be best not to jump around. For me there's no reason to walk on it. The side extrusions with a rack can carry 500 lbs.
The GFC has a lower COG.