I used to know a guy who had the original version. He really rated it highly. More money than sense you could say because he had the best gear including all the UK in both OSGB scales, screen protector (well you get one for your phone) and a satmap branded carry case. Basically all the extras they do.
Since getting it he used to leave his maps in his rucksack because he found the satmap was good enough. That was when most other GPS units didn't do mapping or at least not as comprehensively as they do now.
Fragile? No idea but that guy never had any problem in the few years I knew him. Another guy I knew had one, he was a fell runner/mountain marathon runner. He used to take it on runs attached to a bag around his waist (can't remember how this long since). Never had problems. They both rated the unit, original version not the newer one.
Personally the touchscreen versions of Garmin GPS units I'd worry about being fragile. IIRC satmap use toughened glass screen (might be gorilla glass). Plus you can get the best screen cover too. If you're hard on electronics then I doubt any of the modern units are that much tougher than the rest. Could be wrong.
Personally I don't like the satmap GPS units. I think Garmin are neater.
Anyone know what happened to Lowrance GPS? They were actually the biggest GPS producer in the world and got into handheld units for awhile. Generally they were better, quicker to pick up satellites, more channels, etc. All for less money than Garmin. I suspect they've gone back to concentrating on marine, industrial and professional GPS equipment. Let the playing field fit Garmin