Why is Donna a witch? I mean, sure, she was off key quite a bit, her "playin" screams scare the bejeesus out of my cats, and she brought along "You ain't Woman Enough," but I always thought that when her harmonies with were on (like Looks Like Rain and some of the 1977 He's Gones) she added a vocal layer that the gd rarely had. If it is the singing, let's not forget Mr. Lesh's singing - not exactly inspired for someone with such musical talents. If it is her personal dramas, what good is a band with out affairs and fights! So why is Donna a witch?
As far as the keys go - Vince bored me to tears. His riffs were fixed and unchanging, vocals unispiring and songs - do I really need to say more than Samba in the Rain?
For what its worth, Brent was the keyboardist that I think of when I think Dead - His playing (think Mr. Fantasy and Red Rooster) and vocals were spot on. Keep in mind that although Brent did that weird piano sample and keyboard, Jerry insisted on playing When Push Comes to Shove and Friend of the Devil and funeral procession pace! If it is not Brent, I would just as soon listen to the boys circa 1970-71 in that transitional phase where there really was no keyboard presence.