In particular this would be useful for Disc. But i think it is relevant for all classes.
Critical information is Damage, Healing, and Damage Taken. Specifically allow us to easily see, and perhaps rank/compare by
Damage + Healing - Damage Taken.
I think this would give a better idea of how you are playing than simple damage or healing, and it would also make it easier to compare hybrid Disc healers to other players.
The player that deals 500k dps, and takes 100k damage. Is he better than the player that does 450k but only takes 50k damage? Raw DPS is important for some fights, but I think an Effective Throughput rating would be generally useful for most fights, and would be nice for Disc.
Why Damage, Healing, and minus Damage Taken? Well some classes have higher self healing, like warlocks. So while they take damage, its not really fair to simply take Damage - Damage taken. The healing DPS does to themselves also means healers don’t need to heal them so much.
Possibly allow the ratio of Damage to be tuned, as Damage is possibly worth less than healing. On aoe fights DPS seems to be about 1.5x healing. While single target it seems more like 1.1x healing. A 1:1 ratio would be a good way to start, but tuning would probably be more accurate for the real value. You could let players tune it themselves. Or you could tune it by something like the average of the ratio between dps and healers. So if DPS does 1.5x the healers. Damage is ‘worth’ 67% the healing on an AoE fight. Whereas single target it is closer to 1:1. Although i think a 1:1 would be a fine place to start, tuning it by ratio I think would also be a useful, more accurate measure.
The intention here would be to
a) Better rank hybrids
b) Better rank players that self recover, or avoid taking extra damage.
Cons-> would potentially penalize players that get hit by randomly targeted mechanics. I still think it would be generally useful, and particularly useful when comparing classes performance. But it would potentially unfairly de-rank/lower their effective performance for players that take non-avoidable damage. As a general metric it would be nice to quickly see though IMO. While not perfect i think it would be at least as good as DPS or Healing as a metric.