All MAN-ATL flights operated, but, I'm told that due to cost bases etc, yield on the route is up, with VS/DL 'very happy' with the results.
In terms of yield, VS has a higher proportion of premium seats with 33 Upper Class and 48 P.E. That's just over 30% of the total seats. DL with the normal configuration was 26 J class and 29 Economy Plus (with a much smaller fare supplement for EP than P.E.) so just under 25% of capacity. So if VS can fill a decent number of those premium seats, and I imagine that was a factor in the decision to switch to VS, then it should certainly help yield, although I've no idea what the situation is on cost bases.
Interesting comments by 110 Cornets about premium demand at MAN.