If they're releasing the remaining episodes of the final season in their own box-set, I can almost accept the release of the 'Season 4 (though not really , as it's only the first half)' set; the thing that annoys me most though is that I already bought Razor, and they've decided to include it in this set. Yeah,
thanks for that...
Anyway, regarding the supposed dip in quality, well Season 2 was as good a tv series as you're going to get, it was a tough act to follow; I felt the resolution of the end of season 2 in the first few episodes of the next season were a little disappointing (I think they could've made so much more of the situation). Also, after the immense action of Series 2, series 3 feels a bit bereft in comparison. This is tha fault not of the shows makers, but of the channel: apparently the writers only wanted a 13 episode season, but the channel directors demanded 24...
Having said that, there are superb moments of drama in the third season, I don't think that any other series allows as much space for the characters develop (even most 'real world' based ones), and the finale is, well, gob-smacking's not the word!
If you watch series 4 (or, what we've seen so far

) expecting a space-ship battle every 5 minutes, then you're going to be crushed. I thought it was brilliant, as it seems to have become this prolonged meditation on mortality and death...
This, to me, just cements that BSG is just the best tv series for looking at just about every political, religious, social, philosophical and ethical issue of modern times, far more effectively than any other TV series this decade.