I’d like to do arenas/mythics as resto, but switch up and play feral when I want to dps as well as balance. I understand the specs have different stat priorities. I am nightfae and I want to craft the convoke legendary. What is a good middle ground for stats that can be useful for all 3 specs? Definitely doing Vers as the #1 stat. Should I do Vers/crit, vers/mast or vers/haste?
There isn’t a great middle ground here, but I would say vers / mastery is the best combination between all three specs, but would yield below average results. You’ll need to squeeze in a bit of haste for resto and balance for them to be any good (but Feral doesn’t do well with stacking haste as it’s their least desirable stat).
i think vers/mastery with at least 25% crit(in Feral, if can more is better)
As the others have said, there isn’t really an ideal combination of stats for those three specs in both PvP and PvE. Versatility is obviously a must in arenas, but isn’t really a priority for any of those specs in PvE. Mastery is a good stat for all three specs, but you’ll want crit for Feral and Haste for Resto, neither of which is really ideal for the other spec.
As others have said vers-mastery is probably the best choice for pvp and m+ if you want to use a single legendary for all 3 specs
The best choice will then be to have other gear to switch out to get the better stats for each spec when you switch.
However one nice thing about resto druid in PvE is that all the stats are more or less equal in value for healing. So really if you want to focus on Feral as your main dps spec then you can gear (aside from weapon/trinkets) more for Feral and just use that gear for resto with little loss compared to having a perfect resto set.
I would try making gear sets for each spec.