I have used the PR4 and stock. I have just put on a Road 5. I ride on the road and with a fair amount of rain so that is why I lean this way. I think if you are are going to do more off road you may appreciate a tire with a bit of that flavour in it.
Regarding freight it is all about volume. I work in distribution so the discounts that can be negotiated are significant.
I've worked in Shipping for 12 years for my employer (Siemens Energy) and seen it all regarding discounts. First with Fedex, then we switched to UPS (corporate decision - world wide). We get killer discounts, it's insane, almost infuriating compared to what regular people have to pay. A lot of our parts have to be overnighted to power plants and are generally heavy/bulky/oddly shaped. I see rates sometimes up around $400-600 for if it were you or me shipping it, then it says negotiated total down to like $75-150. A box like I have for those 2 Michelin tires could probably be overnighted via UPS to Mesa AZ for a measly $35, Ground probably $10. Crazy really.
Funny story since we're here. We get killer discount treatment, but what we don't get is any slack when it comes to oversized packages. Not just packages that meet large package criteria, packages that exceed the girth measurement of 165" per UPS, which means they are packages too big for them to carry, but they pick them up anyways. We (used to) ship a lot of very large gaskets in flat boxes measuring around 79"x49"x3-4". Well even though the drivers still pick them up, our accounting department didn't catch all the oversize fees racking up. They used to not charge one, then started a couple years ago. $800 per package for an oversize fee, on top of regular shipping charges, so around $1,000 to ship a large set of gaskets overnight to a power plant in the US. We racked up over $40k of oversized fees in 2018....so we had to totally change our process to avoid those charges. What a mess it was.
I feel like it's kind of crazy to charge the general public so much to ship normal size packages and let companies ship for pennies on the dollar compared to normal rates. I'd sure ship a whole lot more stuff if shipping wasn't so high. So since it is, I ship very few items. You'd think they could lower the price to the general public a little and increase volume. But thanks to the Unions and the Federal Government (USPS), we pay high shipping costs. USPS rates are cheaper than UPS and Fedex, but are still somewhat high if you are shipping anything above the size of a shoe box. And to think that USPS is the largest government subsidized operation makes me even madder. They let all the USPS employees make good money and pay for great retirement, show a huge loss virtually every year, but keeps on trucking and will do the same thing next year. Brief research will bring up articles about how the government does not subsidize the USPS (conveniently on their website), but a study of their financial losses over the years that keeps getting covered by the federal government makes it clear what's happening. First heard about that from my accounting teacher a few years ago. I thought "there's no way USPS doesn't turn a profit"....but I was wrong.
Sorry, I like to chase rabbits when I get to typing. LOL