Yup, been playing ssx 3 and a few others. Running well on the shield. What problems you having? I didn't have to mess with any settings.
Some games work better than others, especially if you start trying to scale the resolution up. Super Mario Sunshine struggles a bit, even if you keep everything at the bare minimum, while Mario Kart and Smash Bros can scale up to 1080p without much issue. Just depends what you want to play.
But as a whole I've been very impressed with the performance.
try using the modified version https://github.com/weihuoya/dolphin/releases
I've gotten some games to run with decent framerates but I consistently have issues with audio. When compared to ppspp or Reicast it's not a great experience.
I play Super Mario Strikers and Wind Waker often enough. The audio can be a little choppy but the game play is fine. I tried tweaking settings to get the audio cleaned up, but went back to default settings. Also, my 2015 Shield TVs are a better Dolphin experience than the 2017's. Fewer instances of choppy audio in the same games.
9230 was playing Viewtiful Joe quite nicely last night. The intro video doesn't play, but gameplay is fine except for a few stutters while compiling textures at the beginning of the minibosses. It's the only game of mine I have ripped, so I can't say whether anything else works or not. ;)
I tried about a year ago and it ran like crap, not tried since
I've not tried, but ETA Prime on YouTube has done several videos about Dolphin on the Shield. If you are having issues I would definitely check those out.