As a motorcyclist and sailor, their hardware is second to none in terms of build quality and robustness. The ability to look down at my Zumo GPS on my motorcycle in a rain storm on a dirt road and have it respond to my wet dirty glove is a close to magic as you will get.
Then there's the watches, the Instinct range is ok but I have a button that doesn't pop back out, my wife's vivoactive suffered the well known touch failure.
However, as a UXer I will say that across all products the software interaction model sucks balls. "China" can and will produce hardware to meet a price point, its not that they can't build good products.
As soon as "China" figures out how to do good UX, the last moat western companies have will fall.
I don't know about UX, but I've had my Coros watch for a few weeks now and I didn't find it hard to understand. I think it's much easier than when I first learned to use a Fenix watch. It misses some Garmin features though that I'd really like to see like off-course rerouting. But like I said above, they have been adding features at a good pace and a drastically undercutting Garmin on price (most watches less than half the price of the closest Garmin watch).