The title pretty much says it; with all the changes to abilities and their scaling, it is now even more impossible to tell where ability damage comes from and how to build your character.
Some magicka skills use weapon damage and weapon crit for all or some part of their damage, ultimates now allegedly scale with some combination of stamina, magicka and/or weapon/spell damage, and nobody really knows anythhing about mundus stones apparently.
All those systems are not neccessarily to complicated by themselves, but IMO, there is far too few information to manage them. I understand that design has to appeal to the most superficial possible user who doesn't want to have to deal with numbers at any cost, but for those who want to, it has become a hassle to find out and keep track of how stuff works.
Personally, I'd very much appreciate a "detailed tooltips" toggle, somewhere deeply hidden in the interface options or really just in the api, so nobody who doesn't want it has to concern themselves with it is forced to see it.