I've only tried the Bolt and have (mostly) been very happy with it. The only Garmin I've used in the somewhat distant past was an Edge 705 and then an Etrex HCx unit - I found both of these much more clunky to use, though the Etrex slightly less so. After the Garmins I just used my smartphone in a waterproof/shockproof case in a mount on my handlebars, but with my most recent phone upgrade (a Google Pixel), I decided I didn't like having a large expensive phone on my handlebars, and also wanted something that worked better in the wet (buttons), was easier to read in sunlight (LCD screen) and had a better battery life (I do have a Schmidt dyno hub and means to convert to USB, but I don't always want to deal with the faff of all the cables).
From what I've read, the main downsides of the original Elemnt are that the buttons are very spongy, with little tactile response and the beeper is far to quiet - both of these issues are fixed in the Bolt, which has a very positive response to the buttons and a load beep. Some also thought that the original Elemnt was too large and ugly, but I guess that's subjective.
My Bolt has been pretty reliable, it's cocked-up on a few rides, not recording the whole route for some reason (or at least not recording the all the track, despite displaying the total distance traveled fine), but I think it's only done this 3 times and not recently, even on some long rides. Don't think it's ever crashed as such.
I like how it's very fit-and-forget, as well as for use on long leisure rides and short tours, I use it everyday as a kind of odometer, and it records and uploads to Strava (and RidewithGPS) without me having to do anything, apart from remembering to turn it on and press "start" on the device (which it reminds you to do with bright flashing LEDS if you start moving with it on and haven't pressed start..).
I usually plan routes in RideWithGPS and the integration is very good with that, with turn-by-turn directions provided (and associated beeps) as well as the snake to follow on the map and coloured LEDS showing which way to turn, or to go straight on. I wish the RideWithGPS Android app was better for route-planning, though - this is still best done on a PC, though if you do need routing to somewhere quickly when on the move, the Elemnt Android (and presumably iOS) app does have a route-finder (think it uses Google Maps under the hood) which you can use to create a new route and send to the Elemnt - the routing is better with RideWithGPS, though.
The maps on the device are mostly fine, if following a route, street names would be nice, but would probably be impossible to read on such a small screen and if using RideWithGPS routes, the text prompts do usually give the street name. I do miss being able to pan the map, though if I really need to do that, I just get out my Android phone and use the one of the mapping apps on that to check where I am etc.
As well as the routing and trip-recording, it works very well as a "cycle computer", with all the functions you would expect, but displayed very clearly (without annoying reflections) and it has a neat zoom in/out feature which lets you quickly see additional (or fewer) fields, adapting the font size automatically. The smart phone apps make the configuration of the device very easy, including which fields to display and in which order. The is no built in real "odometer" function, though I kind of use the Strava integration for that.
Basically, I'm very happy with my Bolt, especially for the relatively reasonable price, and I'm still glad I went for the Bolt, rather than the older Elemnt. After the fiasco of the Garmin 820 (which I almost bought), and my previous less than satisfactory experiences, I was put off buying a Garmin, though the new 1030 sounds pretty decent, though is larger really than I want for a bike GPS unit.
