Paid my first visit to DSA last week.
It's an impressive sight, seeing a wholly new civil airport in the UK. The facilities seem good, and the catchment area is reasonable, so it could do well.
However, access it truly awful. Arriving on the A1M from the north, I was taken on a 15 mile round trip, in a huge circle, to get to DSA. Also, the approach is through a residential area (presumably the old Finningley base).
If DSA wants to expand, it will have to address these issues.