Honestly, I think some aspects of the show, where it is now, have benefited from the gradual build up. Don't get me wrong; there have been a few episodes that truly were filler; but really, I think only 2 or 3. Not two thirds of an entire season like the super cynical fans rant about.
The moment that crystallized this for me was when everyone walked into the bridge for the first time, and the moment of realization dawned on what Rush had been hiding. From that moment forward I feel the writing has seriously capitalized on the built up tension, despair, stress, panic, and anger everyone has been going through for the first season. I think what has become the "bridge crew" for the moment isn't getting enough credit - that's a unique character dynamic of four people (counting Eli too) who were all going through their own crap for a year on that ship having found a purpose and creating a new community.
There's a lot of character development going on right now in fact, at high speed; and while impatient viewers are just saying "well finally, show sucked until now", wonder if folks realize this payoff is so meaningful because of what has come before it. All the stuff we're seeing come out in most of the core characters has weight and gravity because of the shared history the crew has at this point.
But, then, I haven't been one of those who believes it's a terrible cast of characters who are unlikable. The characters are more complex and frankly, not as cartoonish as the characters in SG-1 and Atlantis. The only character who remains a burden IMHO is Chloe; she's the most aggravating stereotype in the crew, who for the moment remains SGU's Wesley.
Sometimes I think if a show like Babylon 5 was broadcast today, people would never give it a chance and harp constantly that it was going nowhere. Season 3 would roll around and when there was finally an outright battle with the Shadows, folks would be grouching that "finally! Why didn't this happen in episode 3! No, forget that, Episode 1!!" And that's even taking into account B5's (for the sake of this analogy) weak first season, which wasn't all that weak when the tons of callbacks began to fall into place.
Gah; I still think that a lot of people are just determined to hate on SGU because it's not SG-1, that's all there is to it. That's fans for you.