I push hp5+ to 1600 and 3200 quite a bit mostly for night sports. They print well. I use Ilford DDX and a JOBO processor. I don't have access to the times that I was using, but I could get them to you.(posted 8250 days ago)I sell the prints and ecveryone is happy with them, so I must assume that to the buyer the grain is acceptable.
If you are interested, email me and I will try to gather up the information.