I definitely think the loss of RJD will be felt by many and for a long time. He was truly one of the godfathers of Metal and such an intelligent and classy gentleman as well.
I've been a Dio fan for many years now, I especially loved his tenure in RAINBOW, and I even have the "Trying To Burn The Sun" and "Carolina County Ball" records by ELF on vinyl. I regularly listen to Dio's stuff anyhow but I think I'll be giving it extra spins this week. R.I.P