Okay, this isn't a review of SMS Backup & Restore. I'll make a review for it later. Promise.
I've been using this app to backup all my SMS. Wanna take a guess at how many SMS messages I have backed up right now? 30,000? Go higher. 50,000? Higher. I have over 70,000 SMS entries in my backup. And that's after using this clean up Python script I made to filter out duplicates!