I'm running a campaign on leadbolt & airpush - same targeting and push ads for both.
When I start looking at the data to optimize, what converts on one is dead opposite of the other. For example carriers on leadbolt which do well are toast on airpush and vice-versa.
Is there some kind of technical reason for this (e.g. how carriers handle billing or a particular network's push ads in general)?

I have noticed that too. It would be nice to get some info on that..))
I've noticed that there is a lot more Wi-Fi traffic on Airpush when compared to leadbolt.. if your offer doesn't accept Wi-Fi traffic then that might explain some of the differences you're seeing.
Different apps, different ad styles and push methods.
How do I get leadbolt and airpush to start showing on my android phone? Are there certain apps I install?
http://www.appbrain.com/stats/libraries/ad
Got to be the context e.g. the app / game in which the ads are running off as the one like @nissangtr suggests