I've always had trouble with people comparing both.
I'm a huge fan of both. But i have a lot of trouble saying which one is better. I never saw the dead, im too young, but ive seen Furthur and i've done tour with phish.
Every jam band is different, and i must admit, both of these bands are amazing!!
But any ways, i'll be on phish tour this summer, then heading out West to catch some good Furthur!