I have had a Garmin 500, 1000, and Fenix 5x in the past and really liked the 500 and the Fenix. I didn't like the 1000 and had a lot of issues with it...wound up selling it. The Fenix watch was really great and worked well when riding mtb or cyclocross, but when riding with a group and trying to keep pace I found not being able to see my speed without moving my arm was a small issue. I think a dedicated bike computer is the better tool in a group ride or paceline when you just want to see the data all the time. I never had a technical issue with the Fenix 5x though. I didn't really like the garmin connect website though and have since imported all my data into my TrainerRoad account, so that is the website I look at for data analysis now. I have no use for strava, so can't comment on any functionality related to it with either units.
I just picked up a Wahoo Element Roam last week and have been on two rides so far with it. I really like certain basic things about the unit. One, I would rather have buttons than a touch screen on a bike computer, and the Roam has that. I love the zoom in out feature on the Roam. It is just super easy to go from three display fields to the maximum, which is a lot (I don't even know right now because I don't have the unit on me). Two, it is also really easy to setup your screens using the smartphone app. In fact, it seems really easy to do everything on that app and it transfers it to the Roam unit pretty much instantly. Setting up a route with the app and putting it onto the head unit could not be easier. The third reason I wanted the Wahoo Roam was that I have a Wahoo Kickr trainer too, and I want to be able to run the trainer using the head unit sometimes. You may be able to do this on current garmin units too, but I kinda wanted to stick with the same company as the smarttrainer.
I like the display in that it is really easy to read even in direct sunlight. I just yesterday setup the side leds to show my heart rate zones and that worked great. Basically it is an easy to understand display that tells you when to back off or push harder depending on what you want to get out of your ride that day. Pretty cool. So far the Roam seems to have all the features I want and they seem really easy to use to.
Using Wahoo's companion app with the Roam seems to make everything including routing, display changes, super simple and very easy to use. I'm new to it really, but have yet to come into an issue with it.
I'm not sure about current Garmin computers, but this one came with a really nice out front mount. If I remember correctly, I think I had to purchase that separately with my past Garmin units.