Mike, I monitor my dive time and my profile in my head as I dive. I don't use a computer to determine my no deco limits or the shape of my dive. So having my dive time easily available is key. Time is also gas; I can usually tell you, based on starting gas, profile and time, how much is in my tank, and I'm often accurate to within 100 psi. It's an awfully nice facility, and ones gauges become backups.
As stated, I use my computer on my right wrist, so that it can be watched while ascending and leave the left hand free to use the inflator or dump valve.
I would HIGHLY recommend trying to borrow and try a gauge with a digital compass in it, before you pay any additional money for that capacity. I've been totally underwhelmed by both of the ones I've tried.