I have RCVs. They recently updated their website and they hadn't been offering them for quite awhile. Therefore the pricing on poly may not be accurate (poly has listed them forever even though they weren't offering them for Yotas 2010-11). We got one of the first revised prototype sets mid last year.
I'll first say we went with these cause the Camburg LT kit would cycle 14" of travel but the extended axle/cv would bind at droop on the tripod and the rollers would pull out at bump limiting us to 13.25" of travel. Went with these because 1. We wanted to see if the joint really allowed that much more angular movment and 2. I am considering using a similar setup for a future project and this was a cheaper test bed.
RCV was very supportive in getting the axles to meet my expectations at this point. It took a few tries to get things setup the way we wanted, but they never charged for making any of the modifications we requested or replacing parts.
Dan @ RCV was great in getting custom modifications that we requested in order to get everything dialed in and I have no doubt that they'd support the product if an issue came up. The setup does now cycle a clean 14" of travel.
That being said I have yet to test them out (first trip out with the new setup is this weekend) and see how they hold up. So, I'll reserve my judgement/comments until then. The 930 joint is pretty much maxed out at the travel I'm seeing, so I'm not sure there's much more inherent strength at the extreme (inner wasn't normally the OEM end failing tho). However, I'm pretty confident the d60 bell on the outer should hold up well compared to the OEM rzeppa outer.
If you guys have more detailed questions shoot me a pm.