Got an Executioner around 2 weeks ago, it is excellent.
I have not yet used it much, out and about, just at home with my 24" monitor, 5.1 speakers, G15 keyboard and G5 mouse. I'm using a dock/fan aluminum CoolerMaster, I got it for $30 on NewEgg I think. As far as a padded backpack for it I've had a hard time finding one that will fit it, tried two different Oakley bags, the Icon and the AP Sand Bag. Ended up sticking with the one it came with, which does the job, just isn't a backpack like I wanted.
I could not be happier with it, so far. I got the performance gain I hoped for compared to my desktop:
zalman copper heatsink'd x800 pro and p4 3.0E, 1.5Ghz DDR 400 hyperX, asus p4p800-e deluxe...
Gaming is great. It plays everything I've tried on it very smooth.
Executioner:
BF2 at (command line widescreen) 1920*1200 (in game settings at 1600*1200) w/ 4xAA and High everything, 100% distance,
with display (quality) "performance & quality settings",
online 64 persons, map "Operation Road Rage" was
getting between 40-70fps and looks amazing, all eye candy.
-- after probably 30 minutes, I did start to get some artifacts and certain color distortions so I stopped, turned off the fancy new advanced settings like "transparency" and "Gamma correct" antialiasings and haven't had the glitches since, I've turned a few things down to medium in the game settings as well and have played for hours with solid 50-80fps butter smooth; no artifacts.
Desktop:
BF2 same map, 64 persons at 1920*1200 w/ AA off and Low everything, 100% distance,
with display (performance) "performance & quality settings"
gets between 30-50 and looked good but almost no grass and no texture, geometry, lighting or details.
*CS:S is 60-100fps smooth everything maxed 1920*1200. Desktop same settings was anywhere from 25-80fps.
The sound is very good as well and is easy to adjust the out-ports to be whatever/where-ever you need them to be.
The screen is awesome as well, I got the WUXGA+ so I could get the full 1920*1200 to output to my monitor (the WSXGA+ will output up to 1680*1050).
It was a pricey buy, but versus the same specs from Dell or anyone else, you just don't get all of it, like you do with the Executioner; for the price.
I am very happy I dished it out. Safeware.com will insure it too, if you want/need that.