10.0 talent tree looks awesome, but it will make adjusting your playstyle within one spec more difficult with so many options available to you. I want the old version of dual spec back to compensate.
When dual spec was first added, you could select your spec, get dual spec, select your second spec, and that secondary spec could be the same as primary. This was a wonderful tool for having two versions of one spec. I used this extensively for PvE and PvP bar/talent setups. When they changed dual spec to just allow spec swapping anytime, you could no longer have two versions of the same spec. This was fine as they significantly cut back on the number of options within a spec, meaning you could easily manually change all options to fit some other playstyle. With more extensive talent trees, there may be a LOT of things you have to manually change to go from your preferred PvE setup to your PvP setup (or single target/AoE, Raiding/Mythics, etc).
Best solution is to give each toon three specs (or four to be fair to druids), and let us choose each one, meaning I could have a warlock that’s Affliction/Affliction/Destro for example.