And penalize players who switch when the teams are unbalanced as well as reward players who stack. But generally you will find all the great players have really good win/loss ratios, so it’s still relevant.
Excluding issues with exploitation, XP/Hr would work better if the XP awards are balanced across the classes (i.e. a Soldier doing a great job earns equal XP as a medic also doing a great job). But it’s also more complicated than that because when XP is used as a pure incentive it displaces some of the skill based aspects. Examples: Giving XP to switch to the objective class, giving XP to change sides when teams are unbalanced, giving one class more XP because in general that class plays a more important role (medics?), etc.
That said it’s pretty much the best option and of course (unless I am mistaken) this is what SD plans on using for the leaderboards, so hopefully there’s some attention paid to balancing it from class to class.
A long time ago I was trying to set up a web site to track XP on ETQW by class, so I could run my own experiment and see if one particular class tended to garner more XP than others. I found though in ETQW it was impossible because the XP wasn’t tracked by class (except for class specific actions). In other words, if you killed some guy with an AR, you had no idea by looking at the stats if you did it as a medic or an engy or some other class.
Hopefully SD sets up their leaderboards segregated by class so it’s possible to compare from class to class and balance the XP awards over time. So you would have, Best Soldier, Best Medic, Best Engineer and Best Operative. Going further, to be best over-all you could say you had to excel in more than one class, so some guy who just plays a single class all the time (maybe it’s the one which tends to generate more XP/hr than the others) doesn’t dominate the leaderboards. Oh wait, they said no global leaderboards right (except I guess for the special missions or whatever they are called)?
Doing it this way would let you do things like give more XP to the soldier for killing (because that’s his primary job) to offset the lack of XP he might get compared to say a medic who is getting tons for rezzing guys.