I've not seen the Ocean Group dub of the episodes up until the start of the Androids saga.
I do know Brian Drummond was Vegeta for the Funimation dub until the voices changed, possibly due to Brian Drummond leaving Funimation for Ocean Group? And he did the voice of Vegeta for the Ocean Group right until the end.
We got messed around with in the UK. We got the US dub then the Canadian dub...
It went something like this:
From the start of the Saiyan saga to the start of the Androids saga: Funimation dub
From the start of the Androids saga to the end of the Cell saga: Ocean dub
From the start of the "Great Saiyaman" (very start of Majin Buu) saga to the end of the "Fusion" saga: Funimation dub
Then they decided to go back to the beginning of one of the sagas (Not sure if it was back to the start of the Great Saiyaman saga or not) then:
From wherever they went back to to the end of the Kid Buu saga: Ocean dub (They may even have got to the end of the Fusion saga then waited a while again before finishing)
But it was really annoying, it seemed like we were getting like 4 voices changes for some characters.
But then, we did get to see the end of DBZ (on the awesome channel, CNX) before the US on Cartoon Network, but still...
Later Cartoon Network (or was it "Toonami", yes it got it's own channel for a while, probably what replaced CNX :( ...) showed all the movies in order dubbed. Funimation hadn't even finished dubbing all the movies at that time. I didn't watch them, but I seen small bits from the first...
It wasn't even the Ocean dub. I don't know who dubbed it (A dutch company I think) but the voices were AWFUL. THey were just so horrible sounding. They called Piccolo "BIG GREEN"!
Big Green, for fuck's sake!
There were other awful changes too. Thankfully I can't remember those. I think it was Krillin sounding... oh yeah, like a child or something stupid. They were so bad.