I just wrapped up the second volume a couple of days ago. I'd say that what you're hearing is correct: Stephenson's writing seemed to even out, like it took him the first thousand pages of the first volume just to find his stride.

While avoiding spoilers, I can say that the story continues, as it should in a middle volume. Jack's adventures become more sweeping, Eliza's intrigues more intricate and Machiavellian.

I have not the slightest clue where this is going to end up, and I think that's the main thing that keeps me reading. It makes me realize how often novels are formulaic, and how I often have a pretty good idea where it's going to end up, at least in general.

I remember, years ago, when I read "Snow Crash", seeing signs of future genius. I don't know as I'd call the Baroque Cycle genius (based on 2/3 knowledge), but it seems like Stephenson might be finding his best form in the epic multi-volume novel. I could see signs of the style in "Cryptonomicon", the intricately-tangled plot, the historical background, the strange but not-quite-gonzo detours...

All in all, I'd give it two thumbs up and recommend you continue.