Wheeling style makes a huge difference. I'm in Arkansas and we don't have the crazy trails like they do out west but we do have lots of beautiful trails here with a lot of mud and rocky hill climbs. We do have some great off-road parks for the rock crawling lovers.
I have a D30 up front with C-Gussets, 4.88s, and a lunchbox locker running 35 inch Toyo MTs. I've been running this setup for almost two years now and it's been great. However... I do know the limitations and am very gentle when playing at the parks which only happens every few months. For the most part I like to go exploring in the Ozarks and have found some amazing trails there that have made me glad I have the locker for the extra traction in the mud and hills.
I don't have the money to upgrade to a 44 right now and I fully expect that one day my D30 will go boom. I run the stock shafts to keep that as the hopeful weak point when and if it does happen. I also know how to do any necessary trail repairs myself to get me home. I wouldn't necessarily recommend this setup to someone else but it works for me and the wheeling I do and I know the risks I'm taking with it. And I would never run 37s with my current setup.
But the truth is, depending on your wheeling style, you could break a PR60 if you wheeled hard enough.