I picked extreme angles for the pictures, didn't want to offend or confuse you In terms of sweat, Yes, my hand get sweaty and my palms as well ... but I am not doing any extreme cardio on the bike and it works out for me very well ... i wipe the keyboard clean with an disinfectant and voila ...
Unfortunately the laptop is NOT secured tightly AT ALL ... If i leave it standing, it barely holds its balance and I always have my hands close-by and when i am exercising and using it, i just put the weight of my fore-arm on it and the balance is achieved.
Having the laptop while working out, is a real luxury. It helps me get through the exercise with much ease. Again, this is not extreme cardio where sweat is flying everywhere.