I've used the manual migration script approaches before (Active Record, DBDeploy), which are really reliable providing you use them religiously to perform all changes. However it's a lot of work and it's easy to accidentally make a change directly to the local dev DB and then either forget to commit a change script or commit a change that isn't quite what you did.

At the other end the automated comparison/migration tools are much more convenient. However they just can't work in 100% of cases, for example thinking a rename is a drop and a create, or splitting data.

I've always ended up with a hybrid approach in the past