[Tongue Pirate]

Sounds about right but all are very different cars. Some people are really concerned with accuracy & that "real cobra" look. If this is your concern ERA make about as accurate a body as you will find. The down side of ERA is the wait!!! They are usually pretty backlogged.
SPF makes a real solid car & have a very strong customer base. Superformance owners seem to be very happy & proud of their cars. I would say that the downfall of the Superformance car is that it doesn't come in a kit form. I would guess that most of these cars are bought turnkey through a dealer. They are marketed for the enthusiast who would probably never finish a kit if they bought one but have the type of money it takes to own a $50,000 sportscar.
FFR's gig seems to be to appeal to the guy who has the time & the willingness to assemble a car from kit form with the possibly to do it on a budget. FFR can be a real nice looking car if assembled well. I have seen a few real nice FFR cars & a few not so nice.

One thing to remember is that some cars will not fit taller drivers well. I believe that all of the above manufacturers car's will fit taller guys but some won't. I am a hair over 6' & I have sat in cars that I would not be able to drive due to the lack of room. Some manufacturers stretch the wheel base, some lenghten the footboxes or lower the floorboards.