When my computer died a few weeks ago, we decided the replacement should be an upgrade. We went with a widescreen and a flat screen next to it. Our work involves using two programs simultaneously. Side by side screens makes perfect sense. It takes a few more minutes to carry in and set up, but when I'm working now, I have all the information I need right in front of me. I find I don't even carry the printer in to the job site any more.
The fieldwork on my jobs seems to be going faster. The evidence is only anecdotal, but it's looking like this was a good investment.