Got the 2689LMT model - quite disappointing so far.
I just bought the 2689LMT, 6 inch version. On first impression, it is not as user friendly as my current 3790T model. Garmin seem to make changes to some good bits like the cable connection. Instead of connecting to the base, it now connects to the GPS which is a pain. They have also changed some of the familiar menu system. Again, very unnecessary. The only good bit I like about the 2689 so far is the fact it tells me which street I am on at the bottom of the screen. Other than that and a bigger screen, I can't see any improvement. Quite a disappointing purchase so far.
I have yet to use its many other features. I probably won't just like I did not use other features of the 3790t. I prefer to use the GPS as strictly GPS, not Bluetooth or all its other features as I am not so electronic savvy. Hopefully as I use it more, I will come to like it better.