Is it really as good as people say?
Depends on what you mean by good? It's pretty dated now (as is any television from the 1970s) both in look and feel (all this dystopian worldview is very much of it's time). However, I've got the first series on DVD and I enjoyed it (I'm only old enough to remember when it had Avon as the leader not Blake and subsequently being confused by the title!) and I hope to get the second series in the not too distant future...
Also, I think you'll find that the first series is up on youtube.
I started watching it last Sunday and now I'm up to Series 1 Episode 7. I think it's brilliant. I love the downbeat tetchiness and the strong characterisation. I agree that the special-effects are very, very dated but if you can get past that there is a lot there.The politics are quite complicated too.
The only small problem I've got is that I already know what happens at the very end from having seen it on lots of clip shows.But even that is not a problem because the characters are so interesting that you want to see how they get there and what happens along the way. I highly recommend it and I'm usually only a mild sci-fi fan.