I started the other way round, watching the first two seasons of the Syffy version before I watched the BBC original. I liked the American version a lot, but had a hard time at first getting into the Brit version. But after getting used to the different, harder-edged styles of the Brit actors, I really liked it, maybe even a tad better than "our" version. But you're right, the fourth-season cast hasn't jelled for me either, and now Sally's crossed over and the new girl takes over as house ghost. The fifth is going to be interesting.

I just finished the British BH a week ago, so I'm taking a break to avoid that cross-threading thing before I get into American BH/3. Looking forward to it, especially now that I have this cockeyed parallax view with the British story a year more advanced.