M17x R3 :PROS: Powerhouse system, definitely high-end, and worth every dollar it cost. One of the on-line reviews I read complained about the keyboard flexing. I do not see even a hint of that problem. Perhaps that was an earlier revision of the M17x. This is beyond doubt the best laptop keyboard I have ever used. The display is absolutely fantastic. The system F-A-S-T, which I expected, but still is awesome. The touchpad is very usable, larger than average, with no flex in the palm rest that leads to false clicks.
CONS: The BIOS password doesn't work like any other computer I have owned. It only controls reading and/or altering the BIOS settings. On other PCs, if the user password is set, you have to enter it to boot up the system. This isn't a serious problem, but is a minor annoyance. It is BIG, I had to shop a lot to find a case that would fit it.
I would definitely buy it again (if I didn't get the new M18x instead).
Alienware M18x
PROS : The computer is built on a solid chassis, finally no more plastic, the components are top notch and delivers performance, everything will run perfectly, be it Gaming,3D Design or 2D design, as well as Programming, for people that needs to move around a lot, and need heavy machinery,
CONS : 1. The weight and Size, for some people, this is what keeps them away, however, for those who don´t mind it(me included), this is surely to fit my needs.
2. 460M....Why offer an old Nvidia card, even on SLI its still old and outdated, why not the 485M, it could give a more serious comparision on what to pick for your GPU, the 460M doesn't come close to the 6970 HD at all, neither it offers any appealing option like 3D(for those who care)