I prefer subs.
Maybe it's just me but I do get something out of the Japanese voice acting even if I don't understand everything they're saying. Some performances are so strong they can transgress the language barrier. It's unusual for a dubbed performance to capture more than a fraction of that performance.
IMO English speaking voice actors often have a difficult time breaking out of their cartoonishly inflated vocal training. It doesn't surprise me that James Gunn couldn't find a voice actor for Rocket and that Bradley Cooper did such a great job. Some dubbed anime nowadays hire screen actors, not only for name recognition, but for the quality of the performance.
Still, sometimes screen actors "reinterpret" the roles which is awful. I'm thinking about Suzanne Pleshette who decided to change the gentle character of Zeniba (Spirited Away) into a smarmy witch or when Phil Hartman (RIP) turned JiJi (Kiki's Delivery Service) into a sarcastic scene-chewer that, while funny, violated the spirit and tone of the film. (The re-release of Kiki thankfully chopped out much of Phil's dialogue because of this.)
There are some notable exceptions, of course. Susan Egan dubbed the part of Gina (Porco Rosso) with heartbreaking sensitivity and depth. She honestly overshadowed Michael Keaton who seemed to phone in his performance.
The Japanese voice acting seems more consistent. I always prefer the subs.