Pape replied to the person who asked why be concerned about the relative MER of two funds. Why not just focus on their respective returns.? He answered that it makes sense to accept the higher MER if the fund has a higher return. The problem with this answer is that he is referring to PAST returns. Study the research. They are a very poor predictor of future returns in comparing funds. 

Would you pay 1% more for a fund when you have no idea if it will perform better next year? No! My advice: take your portfolio as a whole and look for ways to lower your overall expenses. Shifting from active to index funds will do this; shifting from mutual funds to ETFs will do so too, if you purchase the latter through a discount broker. In the past year, I reworked my entire portfolio and lowered my overall MER by more than 1%. That 1% goes to me, if my fund choices are just as good as they were before --and they are. On a 5% overall gain, that's 20%, and it compounds over time.