Here's my take on it. If the prequel / flashback story was that important, so ground breaking, why did it get left out in the first place?
When I was a kid watching Star Wars: A New Hope, did I need to know the whole back story of the Clone Wars when Luke is told his father was a star pilot during the war? No I didn't. I somehow survived for over twenty years without knowing. Sometimes I wish I never found out . Thank you so much Episode One.
When writers obscure earlier events in any story it's mysterious and makes you use your imagination. When a writer decides to revisit and fill in these holes in canon, they remove the mystery and magic associated with them.
In the case of Razor, why the hell do you need to know what happened in the middle of season two when season four is about to start? If this was a stand alone film that aired during season two I would have loved it. Two years later it's lost most of it's relevance for me.
Don't get me wrong, this is still Battlestar Galactica we're talking about and there were some pluses. The opening attack of the war on the shipyards was incredible. The 1970's Cylons make an appearance and there was a line about Starbuck right at the end that will no doubt influence season four.
Now all I want is for next season to start so I can see episodes that actually move the story, characters and plot forward. So say we all!