i have used delta 100 almost exclusively for years and always develop in ID11 1:1. the grain is minimal with 6x7 negatives and very difficult to see at all with 8x10 enlargements of 4x5 negs. ID11 is apparently very similar to D76 and on some development charts, times are identical for both, though some consider grain a bit less with ID11. usually, with N negatives, i've found 9 minutes at 68 degrees quite satisfactory for 6x7, and 8.5 minutes good for 4x5 when tray developed in batches of 5 or 6 films (with somewhat more frequent agitation than roll film in a tank). sorry i can't offer any comparisons, but i've been quite happy with the results.

i should add that "difficult to see and minimal" refer to grain observed while focusing under the enlarger with a grain magnifier.