Lost excels at story structure and in building an incredibly complex and surprisingly coherent narrative... which are BSG's weaknesses.
Yes, as far as pure form--the timing of revelations, the impressive interconnected nature of the series where pieces connect to other pieces seamlessly, the painful almost obsessive attention to details, the way flashbacks and flashforwards are interwoven and how they are placed strategically, how situations and paths crossing could seem contrived come off organic and plausibly, the careful timing of introduction of new pieces and characters being folded into the narrative flow at just the moment cueing you to their forthcoming importance, the parallel structure, the way one can step back and from a distance observe and appreciate the way threads come together and fit--no show can top Lost.
I agree BSG is not very well plotted and the format is not as sharp.
At the same time, Lost has (with rare exception) continually failed to build any sort of meaningful relationships or drama between the characters... which is BSG's strength.
While the shows are similar, yes BSG is far more character-driven. I don't think anyone will quarrel with that. In fact, at times it comes across as academic character studies which isn't always that entertaining.
Lost isn't like that. It tries to balance character and plot more than BSG and at the end of the day I think it favors plot more because the focus on all the mysteries and you also have the characters doing a lot of reacting, investigating, being action figures in this big action adventure and serving the plot. But that isn't to say Lost is purely plot-driven and can only be enjoyed for the mysteries, revelations, twists, cliffhangers, inventive writing and plot.
I enjoy the characters on Lost quite a bit. With all the attention on the Big Mysteries, the show has done an excellent job creating characters that are well-defined and amazingly with as large of a cast as it has it has also managed to create interesting histories and personalities for most of the them. And despite the fast-paced nature and all the fantastical stuff going on around them, they still find time to sneak a character moment or tie what is happening with the plot to the characters. Is it necessarily as deep as BSG when it comes to the characters? Maybe not.
Both shows are brilliant... neither is perfect.
No show is perfect and I was never arguing Lost was flawless and BSG was a show riddled with endless problems. I was just sharing my opinion about what I look for and my issues with BSG.
I would personally argue that at the end of the day for me I've enjoyed myself more with Lost and have had less complaints especially in the last two and half seasons than with BSG. I understand how others might feel differently but overall Lost has been more consistent, more entertaining and better balanced between character and plot--at least from my perspective.