I like two of the Garmins I’ve used, a 1000 and now a 1030, but I use them for navigation and wanted units that I could add Topo maps. The maps display better on Garmins as well, IMO.
As maps aren’t your priority the best option is the Bolt. Not sure about intervals though, I’ve never used that. Wahoo has had time to debug what few items ever had issues and they are now selling for $230. The turn-by-turn was always good, the map was just poor. Paired with RideWithGPS and you can get good TBT and it’s known as a rock solid if unexciting unit.