F1 Stealth Model is a slight, I mean slight hp upgrade from the original, eh not worth it, as you can just paint the original F1 in Black or Matte if you wanted to. Huayra handles quite well for the hp and weight of it. Zonda R is also very very quick, but is twitchy the first few gears, if anything I'd rather you get my personal choice of the FXX, sure its about 50ish percent more than the Huayra, but its a much better choice. If you are strapped for cash, go for the Huayra.
