Too many new characters this season. Too much extreme behavior from existing characters. Zero tension. Lousy explanation for the numbers. Boring, inconsistent, and very sloppy overall.
I'm watching BSG for the third time now (picked it up on Blu-ray). The remarkably even-toned writing and amazing consistency over the course of the show put Lost to shame. And the final season is fantastic--especially the ending. Wonderfully agnostic and open-ended.
Lost is a mess. I'm only watching to see the end, and I doubt I'll ever revisit the series in the future.