Post Processing Computer Selection

Currently I am doing all my post processing on my work computer (I own the company) because I do not have anything at home with the horsepower. Unfortunately that means a 15 minute drive each way so it is hard to sit down and work for just a few minutes. I am looking at buying a new computer for PP at home and I am thinking laptop. So the question is this. How many of you PP on a laptop? The screen I am looking at is 17" 1080P so I am wondering how the image will compare to the 1080P LED monitors I have at work. Do any of you doing your PP on a laptop notice issues with color reproduction, etc? Any thoughts or advice is much appreciated!

Laptop screens generally are not the best choice because of poor viewing angles.
A laptop will always be a compromise between price, performance and portability.

I'd rather get a smaller laptop (for portability when I need it) and an external screen...

What's your budget?
Windows or OSX?

Check out the Retina MBPs. They have a fantastic screen, great connectivity via USB 3 and Thunderbolt (for high speed connections to large drive arrays), and the horsepower to run PS/LR/Aperture or other photo tools.

I happen to love the all flash technology. So I an ordering two maxed out rMBPs (one for me and one for wife) to become our new main computers. WeI will use the SSD space to capture photos in the field and post process them in LR and Nik Suite. When I get home, the files will be moved to the main LR libraries which will be on a Thunderbolt RAID 1 array. The two computer systems will be backed up via Time Machine to a 3TB Time Capsule which will also have a 3TB USB drive connected. What we have not yet decided is how to do a backup offsite....cloud or swap a external drive to a safe location (i.e. bank vault).

To me the only negative on the maxed out rMBP is the significant cost. For us the rMBPS are the ideal laptop to collect photos in the field, post process them, and connect to larger libraries at home via USB 3 or Thunderbolt. They will make great desktop replacements. With that kind of cost, you can bet I already ordered two copies of Apple Care (saved $100 a copy at B&H).

Windows. ALWAYS Windows

Looking at a Dell XPS - Nvidia Graphics

No problem with an external screen. I was thinking about picking up the laptop for now and then adding the external in the near future (probably a 21" or 24")

Actually in all honesty it would be two screens most likely. Used to dual monitors at work, not sure how I lived without them.

My primary computer is a laptop. Post processing as well.

I (personally) use and value Dell Latitudes. I travel for work (a lot, previous Latitude D630 did over 250,000 miles in 3ish years before I upgraded, it never had an issue besides scratches and a few worn out batteries) and would not get anything else unless I was a hard core gamer.

I currently use a Latitude E6420 with an SSD and 8GB of RAM. Never had a performance issue with LR4 or 4.1 unlike many. I use one external monitor in addition to the laptop screen (so basically, dual monitors). I can personally attest to the same laptop running a total of four displays, three externals plus the laptop display. This is with the docking station that has two DVI/two DisplayPort (cant run a display off each, its one or the other) and one VGA port.

Get a laptop with a good screen. Try for 256GB SSD. 8GB RAM is good. Make sure it's got good connections like USB 3.0, eSata, FW800, Thunderbolt, etc. If you don't have one already, buy calibration hardware, like the Spyder.