I am an early adopter - got the eTrex Touch 35, previously had the Dakota 20. I have used it for a couple of weeks and overall my impressions are positive. This includes some touring around France, and PBP.
- although the screen is relatively low res it works for me. Follow the pink line is my usual strategy.
- has a bluetooth connection to my phone, which was great for responding to anxious texts on PBP when the tracking fell over. It flashes the text message up on the screen.
- supports Live Tracking, so my family could follow the blue dot for the first 300km of PBP until it fell over and I did not have the energy to sort it out again.
- syncs with Garmin Connect on the phone via bluetooth and then to Strava.
- records .fit files for those that prefer that format.
- touch screen seems more responsive than the Dakota.
- supplied bike mount is very solid and was not flustered by French speed bumps or cobbles.
- pairs with Ant+ sensors.
- can act as a remote for a Garmin camera (not got one, though, so not tried it)
- did not crash recording PBP (phew!)
- auto start can be switched on and off (did not exist on the Dakota)
The 35 has a barometric altimeter, and microSD card slot. Comes with routable OSM topo mapping for the whole of Europe and a choice of colour schemes.
I ran one set of Lithium and then alkaline batteries - ran for about 12 hours on the Lithium (with Bluetooth on), and more like 8-9 hours with alkaline batteries. Probably would have been more without the bluetooth connection.
I have put it on a usb power meter and looks like it draws 120mA so may run overnight with a Luxos or similar - will have to try it out. I can test that again at some point if folk want to know if it works.
Overall I am quite happy with it so far.