I used to have a Sager 8890. Quite a nice machine for having in college as I changed my residence 6 times in four years. I could never take this computer to class with me though, just too heavy, noisy, and kind of embarrassing.
One things for sure, that computer needed constant maintenance. Cooling was a major issue that required me to have a pretty strict PM schedule. I completely wore that computer out after 5 good years of gaming, coding and rendering. The plastic casing finally gave into thermal wear and my computer split in half once it got too brittle.
I don't ever regret the purchase. I had one of the most powerful portable computers out there, but it did cost me a small fortune. Five years was plenty of life for me, by that point I was out of school and settled in with a more permanent lifestyle, so a desktop was more appropriate.
These mobile computers are a niche market. There was a time it made sense for me to have one. Now it doesn't. Now I prefer powerful desktops and a very lightweight laptop.