I can't comment on the SL-C, other than it's a great looking car and if I had time to build a car, I may very well have purchased the SL-C. I didn't have time so what I do have is an Ultima Can-Am that someone else put the time and effort into. I have to say I'm very pleased with the result. Aesthetically I like the slightly softer rounded(dated) body shape and it is a very capable track car if set up with the rose joint suspension and track rated springs, however, by doing that it becomes less of a street car. It is far more capable than my GT40, but then remember I have an older KVA, so it may not be comparable to today's monocoque's. Yes the Ultima is more 'twitchy' than the GT40, that in part to the 650HP 'all or nothin' engine, but comparing 'Apples to Oranges' a GT40 with that power isn't gonna be much different.
Contact with the factory in the UK has been flawless to date and that depsite the fact I purchased the car as the second owner. That is more than I can say for my experience with a GT40 supplier out of the UK.....but that's a whole other story and 'Parts Shipping' has been beaten to death recently, so I won't go there.
Personally I think Ultima's look better in the flesh than in photo's (and that may equally apply to the SL-C, but I haven't been fortunate enough to see one in the flesh yet). If I could change anything on the Ultima it would be to graft a slightly longer more modern front clip on... ala SL-C. So what's my verdict? Both are good looking and very capable cars. The SL-C's wider array of drivetrain choices and being US manufactured should have greater appeal in the N. American market. The Ultima is already fairly established in the UK market, in part due to the blistering performance records it holds, but given time to establish the SL-C's credibility in hard numbers I'm sure Fran will give the Ultima a run for it's money.....hopefully Ted is developing his product for the future too.