I preferred enh in the BC -> WoD era a lot more than the legion redesign. I don't hate it per say but it is so much dependant on maelstrom... I hope they make us a lot closer to that in 9.0.
One spec that broke my heart is marks. I might get flamed by some who played it more than I did, but I loved marks in legion a whole lot and then BFA came and... I just couldn't find any joy in it.
Many specs that I played around with are not bad per say, but they do feel like their lost part of themselves in BFA.
I really can't wait for 9.0... Hopefully the changes are bigger and better than what they said about it... AKA that there would be no big redesign in 9.0 but mostly adding things back. In the case of enh for example, I could see them making the spec closer to what I loved by simply adding things back such as lightning bolt + chain lightning as finishers (although I'd rather have a new finisher that would work the same but look prettier... maybe crash lightning?). Replace flametongue and frostbrand atacks with frost and flame shock... remove rockbiter, remove maelstrom cost on stormstrike and lava lash, keep strombringer, make lava lash a bigger maelstrom generator but to the point of spammage that RB is (or simply don't and give it some new and nice mechanic instead), etc etc.