Yeah, I've seen a few of these too. I know they don't often use the intercooler. The transfer of heat from the exhaust housing to the compressor housing is not that substantial in comparison to the amount of heat absorbed by compressing the air. The length of the piping surely helps dissapate some heat.
I keep hearing people badmouth these systems, when they don't know what they are talking about. It kills me. Anytime someone does something that goes against the grain, people bash it. The inlet piping isn't that long: Think about it: the car is what, 14'? The turbo is about 18" in from the back, the throttle body is a good 2' from the front, making a distance of about 10.5'. take the piping off your front mount, like pablo said, and I bet its within a couple feet difference. These are great street systems, easy installation and easy removal. Sure, the lag is going to be worse (I've heard its actually very minimal), but on the street its not going to matter.
I think the only thing I'd like to see addressed is the use of the factory steel pipe feeding the exhaust turbine. Its going to rust, and send bits of rust into the wheel at high rpms. So far it doesn't seem to be a problem.
I thought about one of these systems for my Z28. I think if I got one I'd build a stainless sheild for the turbo to keep it drier and more protected from theft and nosy racers.