I'm about 12 hours in on a Honour Mode Gale playthrough, and I can honestly say that I enjoy that. I was rather sceptical, but I like my game.
The reason I picked Gale is because I find him utterly annoying as a companion, constantly yapping as an unreletenting exposition cannon. And, in my first playthrough he kept coming at me saying he wanted to be romantic. So after that, I always skipped him or ate his hand. I also never had Karlach alongside Lae'zel in my active party and being a Wizzie, that suddenly becomes viable.
And, since I'm curious about his story I picked him as my protagonist. It's good! He doesn't yap at *all*, and you actually get his Tressym in camp for the exposition on his quest, who is a lot more fun than actual Gale. The actual value of said exposition is rather weak, though - unless you had him as a companion first, you probably wouldn't understand what his deal is right away. But the cat is fun. Larian really nailed all the animal-speech. I hope the Tressym will interact with Scratch and/or Cub.
Other than that, you get nothing a Wizard Tav wouldn't get, so he is, in essence, rather boring in Act 1/2 as his story doesn't kick in until Act 3.
I'm also positively impressed with how the game improved this patch. So many added things I notice.
