I think the real debate you should have with yourself is portability. If you want it to be portable, definitely go with the MB.
I now have the MB, and it is so much easier to travel with than my last generation MBP. Opening the MBP, leaves very little room in an airplane seat. Often you have to get into an uncomfortable position to see the screen as it will not open far enough.
I got the new MB and I love it. I have not seen any display problems at all. In fact, I used a MBP the other day and thought the screen size was amazing but the display quality was no different than my MB. My MB has an amazing display. I guess there are a few manufacturers and it depends which display you get in the MB as to if it will be quality of the bigger MBP's display. I have the AU Optronics display in my MB.
Traveling with it is so much better. Opening it in tight places is easier and can open all the way to see it well. So, if you need a big display, get the MBP or get the MB and a separate display for use at desk (what I did). If you need firewire, get the MBP. If you need portability, get the MB. If you are a gamer, get the MBP. If you like the MB better, get the MB. If you like the MBP better, get the MBP.
Best wishes whichever way you go. Happy Holidays.