[Brian]

If we're in a situation where both devices have added changes since the last phone sync, the phone ends up essentially re-building the database from scratch in order to merge in the changes from the other device. With the relatively slower processor on the phone, this can take several minutes. We're CPU-bound, not network-bound.

There are some optimizations we want to try in future builds, but for the time being you'll get much better performance if you try to ensure that changes are only happening on one device at a time. Sync changes from the mac to the phone before editing on the phone.