Trying to decide between full back up strategy & differential strategy

I just purchased Paragon HD Manager 11 Suite, and made my first full system image backup the other day. In the past, using a different program, I'd always just done full back ups in order to keep things relatively simple and direct, and never had any problems, other than the possible loss of some E-mails or maybe some program here and there that I'd installed in the interim. I'd try to do a full system backup every few weeks, or before/after any significant changes, and I'd back up data more regularly.

But since Paragon offers incremental and differential back up options, I thought I'd check here to see how that was working out for those who were using that strategy. I was very satisfied with the time it took to make the original full system backup, as well as the time it took to restore it. (Under an hour for both, respectively.)

When it comes to backing up the "C" drive, I'm mainly interested in accuracy, and I have a separate 85GB partition set aside just for image backups. (The "C" drive is around 65GB). In the past, I'd save the very first full back up to serve as the "restore to original condition" option, and make an identical back up on DVDs for good measure. That initial back up would have all of the current -- at the time -- MS updates, along with the personal customizations I'd done in Windows, so it was more complete than the original OS disks. Then I'd accumulate around 4-5 full backups, adding/deleting as time went along. I never had any problems, and was satisfied with the back up/restore times. (I figured 30 minutes to an hour was a small price to pay compared to having to do a totally fresh re-install.) It's just that now I'm wondering if it's time to start using a differential or incremental back up strategy in order to save some space without sacrificing coverage. I saw one thread back in 2010 where someone ended up with a 9 hour restore time from a differential backup, and that would not be worth it. Was that one poster just an exception? (BTW -- my OS is Windows 7 Pro, 32 bit, if that makes any difference.)