Don't worry about the ruggedness of bicycle computers. Any of the 'brand' names are well made and probably will outlive your desire to have the bike it's mounted on. Tens of thousands of miles is very typical. I bought one three years ago and have mounted it on a half a dozen different bikes. Replaced the battery once, and it's still going strong. "Thin and delicate" are not words to be put to a decent bike computer.

Buy the one that suits your needs, strap it on your bike and ride.