Spivac should win this handily in my opinion, don't really see Waldo being that good.
The UFC have manufactured other mediocre heavyweights some pretty respectable win streaks before, not least Martin Buday or Mick Parkin, neither of whom are particularly good.
Spivac's weighed in a little heavier than his last couple of fights which tells me it's all about getting a takedown and working this guy over.
It's not that Waldo is hopeless anywhere, he's just not good, and there should be a visible difference in skill level here IMO.