Ive been using SPB Backup for a couple of months now and have seen some problems. It backs up my HTC Touch Pro with no problems, but restoring is another issue. 50% of the time, the restore fails. I have noticed that if I try and restore the same backup again (after the failure), sometimes it actually works and I get a working restore, sometimes it doesn't. I have also read of others having similar problems here and there.
If I were to do it again, I would buy Sprite, not SPB Backup. I know a bunch of people here love SPB backup, but how many have done more than one or two restores? If you are looking into backup software, and are considering SBP Backup, I suggest you check out their troubleshooting forums... it may change your mind.
http://www.spbclub.com/forum/viewforum.php?f=34