My company went this route. We host own tiles for whole europe, at high level of detail for several of our projects. Thanks to having all data in our own databa

My company went this route. We host own tiles for whole europe, at high level of detail for several of our projects. Thanks to having all data in our own database we can also do geocoding/geodecoding and we've made our own geodecoder (simple postgres query with some some organically grown rules for interpretation of osm data into address). That resulted in 20x faster service for us than from google and just this geodecoding would cost as much as our server colocation (small 8core/32gb machine with 3 cheap ssd in striping configuration).