I've been using the 880 for over a year but recently decided to test drive the 670. I've posted a lot of pics, reviews, and the differences between the 2 at the following links. If you're on the fence maybe this will be of help to you. Personally, I'm going to stick with the 880 because of the nicer screen(displays more info at once), rechargeable batteries, and tilt sensor.
[Link: brothersontech.com][Link: brothersontech.com][Link: brothersontech.com]
