What are his career stats?
I would argue 2008 was his best season.
He is pretty close to Rivera through his first six seasons. Career ERA of 2.35( Mo has 2.21), 219 saves( Mo had 215 through his first six years, not including 1995), and a postseason ERA of 1.00( only due to his bad outing in 2009 postseason).
Do I think Paps can sustain dominance? I don't know. He relies on his fastball and as he ages, he will lose that velocity and his secondary stuff isn't anything to write home about. It is going to be interesting to see how he reinvents himself as he ages.