I happen to use a combination of both, Cardas and AQ RCA caps. On my BHK pre, my Modwright phono pre and my Pass power amp. Both do the intended job equally well in my opinion. I do like the Nautilus logo on the Cardas caps, but I don’t even see those in use. Grab either based on the best price you can find.
I should point out I’ve found the XLR caps to be … problematic. Both vendors insist on a ridge on the XLR cap that I’ve found to be too large and too thick to cleanly click into the socket clip. The cap sits awkwardly on the XLR socket.
My two cents worth.