Yes there are a few who're a running the combo. Not a lot of complaints other than one dude who claims he got 3" or more out of his struts thus they must all suck balls lol. The rest don't post much i gues affraid to say much cause the brand is not well received by most. Same with Ranchos. Somebody posted the isolators crapped out and oh my god what a POS, see i told you i read here or in another forum they suck....
I'm on the very few around who will say i prefer Rancho's ride over the 5100's in many flavors mostly cause i'm not into the disassembly of my struts and prefer a complete strut unit, it's simple that way for my personal taste and the Ranchos ride pretty good. Never had any issues with my Ranchos in the 12k miles i had them mounted in the truck. Now days they're my backup set, when my Kings need maintenance i'll remove them from the truck and send them to my tuner, and to avoid any downtime i'll slap my Ranchos back. Easy install back and forth. I prefer Rancho over RC. If you're on a budget RC is as it cheap as it gets for a lifted strut. $330 for the pair plug and play install. 5100's will be better than RC, and they have a better finish than RC or Rancho if you're into looking at your shock welds lol
Have fun bro.