Hello Im new to the forums and am trying to make a decision on which unit to buy. I want to get the best that is out there but am on a budget, I have seen that the x910 can be $400 cheaper in some places than the Avic 110bt. My question is are there any significant differences between the two besides screen size? If i was to buy the x910 what features would I be missing from the Avic 110bt?

Yes, they are very different. All the differences have been discussed on this forum previously, or you could also go to the manufacturers website and do a direct comparison