It isn't really in the same class though...a GT-One is quicker, faster and handles infinately better than a fully modded Zonda Race car. Same goes for the other two really in that class - the R390 Nissan and that Mazda thingy (can't remember the name).
I would say it is in the same class as the Skybird , NSX, Panoz (?), Supra, Scooby, Lister and all of the 10's of LM cars. It is for the same reason that when you do endurance races, the big 3 dissappear off (behind you obviously ) and leave the other cars (above for example) well behind. In Arcade, I admit they have been placed in the same class but REALLY they aren't though.
Didn't mean to go on but hope you get what I mean. Even your time with the GT-one shows this.
I tell you one thing though, super dupa suft tyres are the make or break for quick laps - I changed (first time ever) to super soft tyres and got a nice 3:34.457 on the complex.