I've used it and it can do things that handmade custom Install Cd's cannot. I'm responsible for making OS install CD's that integrate all patches, all security settings, and profile tweaks. I do it by hand and update every time Microsoft releases updates.

nLite is very nice. You can basically install an OS on a system with everything you need in just a couple of clicks... SO MUCH FASTER!!!!

I still recommend doing it by hand for simple understanding of what is being done, but that is for corporate world.