Every so often my family have the urging to find one of the hard to find and  sparse Rally's in the area. We find one order a bunch of Bufords and Fries and afterwards end up questioning why we went when all we really like is the seasoned fries. But they are decent at times just not great. The franchises are a bit unique to other fast food chains in that they have two drive thrus on each side of the building and only outdoor seating for a window walk up. Not ideal for colder areas if you enjoy eating in.
If you enjoy the drive in type of location I would stick with Sonic if you have one of those nearby. Otherwise don't expect to be overly impressed.