I am Level 76 right now and only few teams are up here and no hard tankers. Only some people who didn't earn promotion one time and other good players. But not tanker with 160+% who stayed in the level several times.
So when I was above 120% average I was guaranteed to be in the hard league next season in my level, from like 3 leagues I have here.
I agree with @milpol that playing the hard way is more fun. But if you push too hard in lower levels, you get many tankers or people who pay a lot in your league, which is then again not real fun. So you have to find your balance, just try out. I would maybe recommend Top 14 average of around 110% for the best experience, but not sure, it depends on a lot of factors.