I am using a laptop with 27 inch external monitor and keyboard (shuttle) connected a raid and it works great ( I mostly work in avchd,hdv,dv) My camera is an af101.
I do events, and comerical, web and currently working on film for a local station. I chose the lap top because of its small footprint and portability (I can edit at the clients place or in the field.
Besides it saves a ton in power versus a desktop. Besides editing I do some compositing and color correction. I Have CS5.5 production premium and avid 6. For what I do both work great.
For this I have a sony vaio fx series 8 core i7 with 8 gbram. It has esata,firewire,usb 3 ans sd card slots.
Will be purchasing a matrox mini as soon as PPro gets it right.
Richard Cardonna