How good is your eyesight? Is anyone over 50 likely to be using the montior much?
The smaller pixels of the 17" display will make it harder to read small text. If you can see if fine then that won't be a problem, but if you can't then you will end up wishing you brought a larger display.
For myslef, I have a 21" CRT on my desk at work, that I run at 1800x1440. Some of my colleges think I am mad, but for me it is great to be able to fit that much desktop real estate on screen, and I can see the small fonts just fine. The company is slowly upgrading people to LCDs, but as they are only 1280x1024, I don't want one, as for me it would be a substantal downgrade