I like your system Chris. Although there isn't a hard backup, the tablets are being synced to multiple masters so often that it's unlikely that there will be any major problems. The email back up is still useful backup even if a competitor isn't monitoring it actively during the shoot. If a score was entered and he tablet was broken before it was synced to the range wide wifi, the shooter could log in to get the emailed log from one of the myriad devices on the range.
Does the email log function work if you are using android tablets then syncing to an iOS master? Would the logs be sent from the master?
It's not my system; but the systems that are developed my Ken Nelson (iOS) and Eugene Kuleshov (Android).
Ken's system uses the Internet to store all of the scores, and those scores are also emailed to competitors. No hard copy is necessary, because all of the scores are saved and can be viewed online. If a device fails, it doesn't matter when it was sync'd, as long as the scores have been logged to the Internet. However, this requires an internet connection and (currently) only works on iOS devices. As far as I can tell, the score logs can only be sent from the device that was used to score the competitor. I tried importing logs from another device, and that didn't work out so well; it's either buggy right now, or I'm misunderstanding the use of the feature.
On the flip side, Eugene's Android version does not currently talk to the Practiscore scorelog website (as far as I know), but instead has other, more user friendly enhancements, including being able to be connected to thermal printers (which are not that expensive, they look like they're around $50 USD) via Bluetooth (and even wifi). A downside is that not all android devices are created equally, and some have horrendous battery life or very dim screens. Also, if a device dies (although I've never seen this be an issue), you lose everything on it that hasn't been sync'd yet. Our club purchased iPads, but personally, I keep an Android tablet as one of the main masters. It has some features (especially the checking for edits) that are far superior to the Apple Version, but syncing back and forth between Android and iPad introduces some weird results.
I'm still going to encourage IPSCBC to purchase a couple of the thermal printers to trial and develop some documentation for setting them up for our clubs that do have Android tablets. Hopefully, they'll also be compatible with future iOS versions of Practiscore as well.