I think Izzy is the second best MW I’ve ever seen – maybe the best. But, I think the Chael Sonnen (PEDs and all) who spent 4.5 rounds beating up Anderson Silva beats Izzy and runs through Vitori.
Izzy is a better technical striker than Silva, IMO. But he lacks the one-strike finishing power Silva had. Silva also had a stronger clinch and a BJJ black belt. I don’t see how Izzy stops the gameplan that Chael executed against Silva.
The x-factor is that Izzy is more mentally tough than Chael, who had a habit of stealing defeat from the jaws of victory. Izzy’s sweeps, for example, aren’t bad. If he got one, we could see Chael fold a bit and get finished.