The Edge 800, expensive, supposedly will handle route downloads from RWGPS without corrupting them. The eTrex will not. I use it with downloaded track files when touring. If I want turn-by-turn thru a city, I plot it within the gps.

I've recently discovered that with Garmin's Basecamp, displaying CNNA, one can create a snap-to-road route that will not be corrupted by the eTrex. This has only been tested once on a 12 mile local ride with several intersection turns. Seems to be a relatively new update for Basecamp, but may be that it is only new to me.

The eTrex 20 cost about $200 and is apparently the latest version of this very solid line. Nothing much about it's ability to manage downloaded turn-by-turn routes. Probably won't, least from online mapping services. CNNA detailed street map is another $100.

I'd order any gps I thought might meet my needs from Amazon. If it didn't measure up, I'd return it for another. Repeat until satisfied. Cost to evaluate would be about $10/return, if Prime eligible.