You can set a Wahoo to upload directly, and automatically, to Strava and RideWithGPS. It will also do the same for a wide range of fitness apps. Most people I know go with Strava.
I'm not very familiar with the Roam. What I can is this.i find the Elemnt black and white screen very easy to read and use. I would not go back a colour screen as I had on my Garmin.
The "Get me Started" function could be useful for getting to the start of a ride when in an unfamiliar area.
The reroute when off track? Well I suppose it has benefits but a flashing red LED for a quarter mile after missing a turn is adequate for me. This is already in the Elemnt.
"Route to Start" to get back to your starting point is useful. I thought but have never used it this could be achieved on the Elemnt by selecting the reverse route option?
I would highly recommend the Elemnt. Mine has never faltered. My experience of Garmin 810 is it became so complex the device would almost confuse itself and constantly fail. Poor set up by the user, I was guilty, made it very difficult to use and the directions as to how to do this very poor. I would not buy another Garmin.
My concern with Wahoo is the Roam could be the start of a road leading to ever more complex devices which become difficult and bloated to use. The beauty of Wahoo is simplicity.