How does the accuracy (as well as address parsing capabilities) compare to the completely free solutions such as Nominatim[1] or DSTK[2]?
Both services provide capabilities for local installations, obviously with no query limits and minimal latency.
We have mostly been running tests against the Google Maps API, and from a totally random sample of 100 address, 90 of them were within a mile from the Google Maps API returned location (Most of them were actually within 0.01 mile).
I'm not sure how we would compare to OpenStreetMaps and Data Science Toolkit since our data source is different (US Census Bureau). - But the obvious reason why we provide this as a SaaS, is that you don't have to host anything yourself, or juggle around with gigabytes of boundary data. We handle all the mess.