Sometimes I need to collaborate with a more frontend-centric developer to help implement a site. So typically they're only changing CSS and minor template changes.
The way we've handled this in the past is that I work locally. When I have everything in a good state, I clone my environment to a staging server. The frontend dev then uploads his changes via sftp.
We'd like to move toward a setup where we're both working locally. The problem of course is keeping the configuration changes all in sync. I have been using Features, but there is still a lot of global configuration that would need to be manually migrated between instances.
I'm not quite ready to make the jump to each of us having a local database. I have considered taking a "half step" by having a shared database that we both connect to over the network.
I've found a few blog posts here and there where people have suggested it, but I thought I'd ask here: have you tried this, and if not, is there's any reason this is a bad idea?