Oh be aware that there a few apps Helium can't back up. Notably, the default messaging app in 4.4.x tends to block backups for some reason. I use SMS Backup and Restore to grab my texts before doing a wipe. Look on Helium's app backup list, at the bottom it'll show what other apps it won't grab. You'll have to find workarounds to preserve the data for those if you need them.