Other than for very specific ergonomic uses, I honestly don't understand the appeal of a heavy mechanical keyboard; the old IBM buckling-spring Model M keyboard doesn't appeal to me at all. Personally, I do all my work on a ThinkPad keyboard, and I actually have a USB ThinkPad keyboard/mouse for use with non-laptop systems or docking stations. I like the short throw of the keys, I like keys close together (as long as my fingers have room to type, which they do on anything >11" or so), and I like having a mouse on home row.