From memory I don't think a great deal was actually changed from the Japanese to the British version of the show. Narratively at least. The necessary changes, from the dub to the soundtrack I've always really liked. Paul Bliss's soundtrack I still feel to this day is incredible and was one of the main factors in differentiating it from the range of Gerry Anderson shows. It really was beautiful work on Paul's part IMO. The dub - I'm a big anime fan, and whilst I enjoy both dub and sub, sometimes I end up going with the dub more often than not as I tend to watch a lot of anime while I'm doing other things. Suffice to say, I know a weak dub when I hear one!
Star Fleet's is very good. The only weakness is with some of the peripheral/background roles where they've obviously utilised the existing voice cast to save more casting, but then they're trying to not sound like themselves and it comes off a little weaker.
To strive, to seek, to find, and not to yield.