Actually, you can say it's lower. I'm a big defender of CIS hockey, and the best CIS teams do beat good NCAA DI teams (see, e.g., UNB, McGill), but there's no doubt that on average the CIS is a lower level of hockey.
As another metric, how many ACHA coaches have moved on to higher levels?
To name two leading examples, Mike Babcock and Mike Keenan both coached CIS before they go to the NHL, and there are dozens of lesser known / successful Asst Coaches and Head Coaches who have done so (e.g., Tom Watt, Wayne Fleming, Kirk Muller, Billy Moores, Jamie Kompon, to name a few).
There are good teams in the ACHA Div. I. But the league is not even close to being on par with any level of the NCAA or the CIS.