Just to add another point of data; accuracy is much worse on after 37xx to 34xx. I had two 37xx units and I flashed one at a time to 34xx and compared them side by side. The 34xx was always showing worse accuracy, sometimes double the 37xx.

I then revered the units and found the same conclusion. (34xx->37xx, 37xx->34xx).

The accuracy of the 34xx is so bad it often causes recalculations because the GPS thinks I'm on another street. Many times when my vehicle is at a full stop, the GPS will show that I am still moving, sometime upto 50km/h for longer than 1 min.

As much as I like the 34xx I will have to revert as the inaccuracy is too great.