Good points. I also swap Ctrl and Alt on both sides, using my thumbs for Ctrl. Using the opposite hand to press the modifier is analogous to how a touch typist

Good points. I also swap Ctrl and Alt on both sides, using my thumbs for Ctrl. Using the opposite hand to press the modifier is analogous to how a touch typist uses the shift keys. For desktop use, I now use a Kinesis keyboard, again with symmetrical modifiers but all as thumb keys.