I've had both Hinderers and ZT/RHK collabs and there IS a difference to me. The 392 blurred the lines a bit more by using more of Hinderers parts, but comparing a 0560 to an XM18 was night and day for me.
First off, I'm not a huge fan of bearings- they work- but I worry about extended functionality.
Second, the ergos on an XM just seemed to fit my hand better.
Third, I can disassemble the XM and even customize it without voiding any warranty.
Again, the 392 covers a lot of these bases too, but it felt... thinner? I was shocked at how small it felt but maybe someone with an Eklipse could chime in on those (never saw an Eklipse in person)
As far as the pricing, the 392 offering isn't far off from RHK MSRP and figure the extra cost is for the exclusivity of his parts and of course a little marketing. The offerings with a larger disparity from RHK in terms of price, as I've said- felt different to me.
Edit: just saw bld said the same on the pricing vs RHK