Related note about courses and my 310XT (Ant+ only).
Summary: Do not by a 300 series Garmin if you ever intend to use courses. Probably don't consider one at all unless you need its swimming capabilities.
There was a multiple-month period of time where the Garmin Express software would crash instead of loading courses. There was another couple of weeks where I could only download my data from the 310XT using the ANT+ support on my phone (and not the dongle on my laptop). My phone would often drop connection in the middle of transfer and require starting over multiple times before it finally got a full data file. As there is no external USB port on this device, I was SOL in both of these cases.
As of now the only way I can load courses is to upload a GPX/TCX as an activity file, turn that into a course on Garmin connect, delete the activity which has now synced to Strava, and then hope the Garmin software loads the course eventually.
(Sidenote: If anyone has figured out how to get turn by turn directions onto a 300 series Garmin, please let me know. I was only able to do it once, a long time ago, and never again.)
~Chris "maybe I should just give up and buy a 510" Merrill