Well you are lucky then. With road salt and mud up here we are lucky to see 40,000klm out of UJoints. Original factory maybe 60,000klm but definitely not from replacements. So far my RCVs have 20,000klm and quiet. Fingers crossed, if they are as bad as you say then I'll change them. Can't see them being any worse then UJoints up here anyway.
I live in Nevada, the driest state in America. Before that, I lived in SoCal and so no, salt and mud aren't an issue for me. Like I said, the sound they make doesn't necessarily mean they're going to break - it just sucks especially when you have to pay a significant premium for something that's supposed to be so much better than a standard u-joint axle. Also, if you twist a spline (I have seen it happen), RCV will tell you that's normal too and won't warranty it. :naw:
Send them back? Rebuild them yourself.
At a $400 premium and with a supposed amazing lifetime warranty, I personally don't feel that I should have to anything especially when I've had factory shafts last 5x as long and without making a sound. Of course, that's just me.
I bought into the hype and have them. I probably would not buy again, but haven't had any problems. I keep them greased and they work fine so far. I have had chromoly shafts and full circle clips on other vehicles and they work fine too. Are RCV's worth the $$$? Probably not. If/when I upgrade my axles I won't buy them again, but they have worked ok. Either way you get a lot less practice changing joints on the trail. Back in the 90's I got pretty good at it. I was so stoked when I got my first set of alloy axles(warn at the time) and solid joints (spicer 297x I think) with full circle clips. Got to wheel longer and harder but eventually broke those too.
Like you, I bought into the hype early on and ran a set of RCV's on the old 2009 JKU we used to have. After having first hand experience with it, I couldn't see myself spending the $400 premium for them when a good set of chromoly shafts with full circle clips would work just as well and for a lot less. While I have broken u-joints, they've all been c-clips and while I have broken chromoly shafts at the shaft, I've yet to break a u-joint with a full circle clip. But then, I'm just a mall crawler.