SNG vs MTT

I'm not too sure if this is a valid question but

Right now im playing the 22s @ about 500 tournaments.

Is there any extra value i can expect if i decide to convert to MTT? I prefer SNG to ring games due to lower variance, and have been getting a steady ROI (17%) in the 22s, so should I spend the extra effort learning MTT or honing my skills on the 22s. I ask this because I can only afford to play approx 2 hours a day max.