I have both Fujimi and Revell Integra. I actually think the Revell kit is better, since Fujimi details are really over simplified, not to mention ride height is way off. They mold a nice set of rubber tires though, and the fit is quite decent. The Revell kit comes with turned metal tailpipe and is actually quite nice, relatively speaking. Revell quality really depends on kit.
As for the Enzo, I have one Revell and three Tamiya, and needless to say, the Tamiya kit is breath taking. The Revell isn't great, but it ain't absolute crap like the Revell 360 kit is either.
I have many kits. It's a matter of construction, and every kit is a learning platform. I want to build an Enzo like the one at www.ItalianHorses.net.