Think about it this way.  Does it matter how many rejects you get if you're getting paid more?

Clever is mining some aggressively fast coins.  More profitable but reject rates get amplified by very fast coins. The reject rates are part of the profitability equation.

Waffle is a conservative pool. It has low reject rates because they DON'T mine the most profitable fast coins.

So in a race between a Bugatti Veyron and a Toyota Prius, do you choose the Prius because it's not as loud?  For me, I don't care if it's louder or more finicky or takes more gas.  If it's a race, I take the Veyron.

So at the end of the day, what's more important to you, the reject rate on your screen or the payout to your wallet?