I personally find a lot of them hit or miss. Mainly misses, though. I really like Elemental & Resto Shaman + Windwalker & Mistweaver Monk + Holy & Ret Paladin right now.
I can't stand my Warlock right now. It seems like every other expansion since Mists I'm hating my Warlock. Mists and Legion felt great, WoD and BfA not so much. I miss my BC/Wrath Lock though. Feels that way for the majority of classes right now.
There's a couple of things I'd like to see reworked, I suppose. Mainly Sub Rogue. I'd really just like to go back to the days of playing your class and not just a spec, like OP, which Shadowlands seems to be attempting to do. We'll see.
Regarding a talent tree revamp, I don't know. I wish they could figure out a cool way to make a mix of the Pre Mop and Post Mop talent trees, and have them be for your class instead of your spec.
(sorry this post is a mess.)
TL;DR They're hit or miss for me. Mainly misses.