I love the idea of a mechanical keyboard but I worry about productivity when I’m on the move.

I find it easier to stick to the laptop keyboard and trackpad even when at a desk plugged into a big monitor.

Everytime I try to switch to a mechanical keyboard and mouse my wrists start hurting. I guess this would go if I got used to the position but then what would happen when I have to use the laptop keyboard?

(So far I’ve tried an IBM model-m and a Pok3r keyboard).

From my experience, my wrists start hurting if I don't use any wrist rests (despite the name, you're supposed to rest your palms on them) Also, tilted or high profile keyboards are less ergonomic IMHO.

Don't worry about switching back to the laptop keyboard on the go. You won't be less productive, you will just enjoy it less :)