I've owned a couple of Luton Minors (300+ hours) and used to fly alongside a FRED regularly. The FRED was not quite as good as the Minor (dreadful glide angle at idle power unlike the Minor) but still gave it's owner bags of fun. If the wing fold is still available it must be a definite plus over the Minor. I remember the FRED pilots frequently complaing about how awkward it was to fill the fuel tank up on top of the wing. It had a bl00dy good endurance though!
Regards
wizzy