I hesitate to comment too much on these things because different people have widely differing expectations of their kit and of course, different budgets and ideas of value-for-money. But anyway .....
I’ve used a Map60 - I still have it as a backup - and was sufficiently satisfied with it to up grade later to a Map62, specifically to get the Ordnance Survey mapping option. In the meantime, I’d tried the Satmap, which was the first to offer the OS facility, but over a considerable period, I found it inadequate for a number of reasons, though it’s good for walking.
I’ve never gone the Extrex/Vista/Legend route, which is more popular, because I liked the buttons-grouped together aspect of the Map60 and I find I can operate it perfectly well with full winter gloves, even mittens, on my hands and in the dark. The extra screen size is also an advantage, I feel - I use reading specs at 1.75 point strength. On the bike I use bi-focals.
The button model screen is slightly more readable than the touchscreen models, although these things are developing with each new model. You’ll be wiping finger grease off the touchscreens more frequently than with button models, but it’s only a small point. Reflection from bright sunlight is a bit more of an issue and I think the button models cope a little better here too.
The mapping you choose will affect the readability. The more heavily detailed OS map is more difficult to read, though often the extra information it delivers can be very helpful. It depends on the type of ride you’re on. If you’ve loaded a clear and definite Route or Track (different subject - a whole can of worms - see elsewhere!) then the non-OS Garmin or open source maps are generally clearer and perfectly adequate. If I want the option to navigate on the fly, I like the more informative OS.
A word of warning about the Map60. Toady is correct; it is very robust. But there can be problems with the unit cutting out over rough road surfaces. I had two Map60s - Garmin eventually gave me a new replacement because the first was plagued with this issue, which other owners have also suffered. Widely thought to be a battery contact thing, I believe the real answer is internal and I haven’t had any such problems with my Map62.
The latest firmware for the Map62 (which can be retro-loaded) includes a photo viewer. I now find this useful as I can scan in a note of various aide-memoire matters and read them on the move if I want - I have a goldfish memory and am prone to worrying about information controls and control closing times. (Other people of course simply pull their Brevet card out of a back pocket but if I do that I just drop the blessed thing and lose it!) The very latest range includes a Map62 with a camera - the influence I suspect of the geo-caching market.
Another thing - the bike mount for the Map60 was a bit of a lash-up and for me, not adequately secure. The Map 62 is a big improvement. The Map62 is undoubtedly a bigger lump than say, the new Etrex models, but the difference in weight isn’t huge. I use tri-bars for comfort and nestled down between these, the Map62 doesn’t look too gross. Like the current Etrex models, it slides into its mount in a fore-and-aft direction, which means it can have lights and other stuff fitted close alongside, which can be useful. The Edge 705 for example goes on sideways, which is a pain in this regard, and I believe the Edge 800 is a twist-type mount, which I guess would need space on both sides. Although with a bit of ingenuity there are usually ways around these snags, it’s helpful not to have to muck about too much with custom mounts.
I hope this helps.