Hi, Bruce,
Yes, I use OpenCPN a lot for planning and as a backup to my Garmin chartplotter. I like it very much. I agree that loading and sync'ing the charts can be a chore, but for me it's more of [re]learning curve thing. Once I dust off my recollection when I need to download a chart, I'm good to go. I plan to keep using it.
V/R
Bill