for a wedding this year, I needed 1600 ASA for indoors and so I tested before: Ilford Delta 3200, HP5 plus and Delta 400 - all rated 1600 ASA. Developpers were Microphen stock solution and DD-X 1+4.
Times were as recommended by Ilford, the Delta 3200 as if rated 3200 ASA.
My result/opinion: Best was Delta 400 in Microphen or DD-X. In Microphen slightly a little bit grainier as in DD-X, but better contrast.
Maybe DD-X would be the winner with a longer time. Developped as recommended by Ilford, the negative becomes rather thin...
HP5 is much grainier in Microphen but great in DD-X!
Delta 3200: forget it, at least rated 1600 ASA...
The picture was taken with my beloved Canon T90 with FD 1,2/50 L and Delta 400, rated 1600/dev. in Microphen stock.
Cheers and "immer gut Licht" to all
Peter