"Auto-routing" is what everyone associates with GPSes, but for me the most valuable feature is that I always have detailed maps handy - I have the whole of Europe on one Micro-SD card. The maps are very good quality and free (no quotation marks). OK so in some ways a small screen isn't a substitute for a map you can spread out on table but great if you need to focus in on a tricky junction.
Another really valuable feature is to be able to download tracks for cycle routes (but beware - there are a lot of rubbish tracks out there).
I also have the locations and contact details for loads of campsites, hostels, etc etc.
I do use auto-routing fr time to time - if I get to a town and I just want the quickest easiest route to the place I'm staying. It works pretty well for that sort of thing, but if I care about the route I'm going to take I plan it myself.
My eTrex has three options for auto-routing: pedestrian, bicycle and car/motor-bike. Probably the Touring has the same options.
When it's in bike mode the eTrex seems to prefer cyleways over roads and cycle routes over other roads, but given the choice of two cycle routes or two ordinary roads it will chose the shortest distance (which may or may not be what you want).
My favourite maps are from openfietsmap.nl (URL from memory), but these things come down to personal preference about the way the map is rendered on the screen - the underlying data is the same.