I use it 1+1 for AEU400 and HP5+. I don't notice excess grain unless things were pretty under exposed. Sometimes I use 1+3 for slower films such as Ilford FP4+ or AEU100 and those have always come out just fine.. I have not yet used it stock as far as I remember.
But I am probably the last person to ask about grain since I already expect to see some with my film anyway. If I were worried about grain then I'd just go digXXXX!