I've had wrist, console and hose-mounted computers. My preference is for wrist mount on my left arm because it makes it easy to check (assuming the digits are large enough) just by tilting my wrist. My right hand carries a camera so it is occupied. I don't like having to use my left hand to reach for a console. This is especially true when I am filming a subject... I like to be able to check deco time at a glance rather than disrupting my filming by reaching.
By the way, if you decide on wrist, make sure the band is a sturdy one or get it bungie-mounted. My Uwatec Aladin Pro wrist strap broke while I was on a dive. Good thing I noticed it right away. Being a starving marine biologist, I decided not to buy another band for $30+ and rigged it up so I could attach it to my console. I'm looking forward to my new wrist mounted Nitek Duo to arrive soon and return my computer to where it belongs... on my wrist!