Yes the AFS is useless, It will hold you back from learning and I have seen it cause problems with trimming the airplane.
Most people here will tell you the first thing to do when getting a Nexstar is disconnect the AFS.
I have not flown the Hobbistar but a club member learned on one this year. It is a floater, it takes off in a short distance and lands slowly.
Yes the wing is 3" longer, the wing surface is 166 sq. in. more and it weighs about 1-1/2 lbs more.
I have flown the Nexstar, Airvista and Brightstar as far as Hobbico airplanes go and all are good flying airplanes. (the Brightstar and airvista are discontinued models.