I don't really like dubs in general. I much prefer watching anything in its original language, but DB has been a particularly painful experience, although over the past several years, the voice actors are the least of its problems. For the most part, the Ocean cast was great. They were good actors, and a lot of them fit the characters. The problem then was Saban's censorship standards, the heavy cutting, and the extreme deviation from the script.
Then season 3 happened, and, even at 13 years old, I was shocked. The voice actors were completely horrible. The censoring was much less, but the script was even more inaccurate, and the music was complete and utter shit. It was because of season 3 that I finally set out to find the Japanese version. Season 4 was a bit better but not by much. By season 5, I had quit watching the dub entirely just because it was so not what DBZ is supposed to be.
Their DB dub was much better. By that time, the actors had gotten better at their roles, and that actually had the sense to keep the original music, so I did watch that on occasion, but, like I said, by that point I'd given up on dubs entirely.
And then there was the travesty that was DBGT. That show's bad enough on its own, but the dub was a complete joke. I've never even seen a complete episode of it. They lost me at their original trailer where they mocked the original version and showed their new hardcore version with the idiotic rap song. They've taken steps now to improve it with the new boxset, but, like I said, I don't care about the dub, so while I'm impressed, I'd still rather watch the original.
So my biggest problem with dubbed Dragon Ball isn't the acting, which, except for Chris Sabat's Vegeta, isn't that bad. My biggest problem is with the script, followed closely by the music.
But my biggest beef with FUNi in recent years is those craptacular "season" boxsets. Since they don't even correspond with the English version seasons, I think they should have just called them "volume"s, but that's not my problem with them. That is, of course, the cropping, followed by the lying about the cropping. They seemed to finally come to their senses with the new DBGT boxset, but since they no longer use alternate angles for some reason, they've screwed that up as well, only having the English song and title cards and no longer having the previews. The old single discs were better!
So no matter what they do, they always screw something up, and it just baffles me why they can't just get their act together!
EDIT: And I should also mention their mispronounciation of words like Kamehameha, Saiyan, and Kaio-ken as well as messed up names like Tenshinhan-->Tien.