I second JMcD ... do NOT trust your buddy's dive computer! Get your own!
What happens if you and your buddy gets separated? (And sooner or later it WILL happen) How will you monitor then your ascent? And your safety stop?
While I also second getting your own computer, the usual buddy separation procedure I've been taught, and will teach in turn involves ascending to the surface without a safety stop. YMMV.
I was taught on tables, taught the wheel in AOW ML dive(one of my electives), and got the eRDPml as a divemaster. The eRPDml does a few things easier than tables, but not by much, and as long as you know the rules, you can calculate multilevel pressure groups on the good old RDP(mind you this is beyond most divers, you have to know the next depth that will give you credit, ie at what depths you change the controlling compaterment), it's faster for me than the eRPDml.
The difference between RDP/Wheel/eRPDml for a given profile is never more than a minute or so anyway, and I don't have a habit of diving to the absolute limits.