These Clevo systems are rebadged by a bunch of different companies: Sager, Alienware, Hypersonic, Prostar ... These are great systems if you need the power and mobility.
I have a Sager 9860 (same casing as this). I take it to client sites every day. It's heavy, but not too much for just walking from the parking lot. And it has a lot of power. I typically run an application server and a database while I'm working, in addition to my IDE, various office apps and music player. If you need the performance, it's worth it.
Of course, if you don't, don't buy it. It's always interesting how so many people assume that they understand the needs of everyone else.