Buckling springs are the baddest asses in town.
You can make many kinds of arguments for and against anything, but there is no denying that IBM Model M/Fs are in a class by themselves.
Not that strength, weight, and durability are the only criteria that matter, but you cannot deny the value of those attributes.
If you need something to slip into the front pocket of a briefcase, or if size or weight matters, well then, you had better look elsewhere.