As far as blowouts on a regular tire vs. ROF's go, I've only had one non-ROF blowout. Back when I was a teenager, I blew a front (tube) tire on a 250 Enduro doing 60+ on gravel. There was NO sidewall on those tires. She folded over and I cranked the steering to a full right lock and it still headed toward the left ditch. I let off the gas and slowed down. Just before I hit the ditch, it flopped over to the other side, I did a full left lock and headed back to my side of the lane and got stopped. Total luck that I didn't get killed.
The Dunlop E3's that I run on the XII may not be runflat's, but they have a very stiff wall. I've never blown one of these, but had a leak and ran it down to about 10 - 15 psi. The tire held up well and I didn't have a problem till I slowed down (it got squirrely at slow speeds).
All I can say is that I would much rather have a Run Flat on the bike than not. Just like having ABS in an emergency stopping situation, the Run Flat makes a puncture situation pretty much a non-critical event. Not sure how it will feel flat, but anything would be better than a critical failure on a weak sidewall tire.
Get the Run Flat. Test it flat if you like as several have done to get a feel for it. I don't even have my setup ready to go yet, but really believe it is worth the investment.