Hello all, I have a Olympus epl2 with 17mm but I'm getting a gx7 for Xmas. Should I sell the 17mm for the 20mm? I used to own to old 20mm and really enjoyed the colors and small form factor over the 17mm. The 17 was just so much faster with focus. Since this isn't a problem anymore which is best? I'm hoping to break even so price shouldn't be a issue.