I have been having download problems for the past year. Some I can blame on my pitiful DSL where I live. The message about check the connection is only for iFly. I could update my Garmin last night, panel mount, so also an SD card update. It takes moments wheras the iFly takes hours, when it downloads. The neighbor is on the same DSL, uses an iPad with Foreflight, and no problems.
I bought my 700 before they were shipping and have been a proponent of iFly since day 1. However, if I had needed the update last night, as I thought I did, it might have changed my mind about my hope and planning to upgrade to a 720.