To be honest, as we're not pushing content and I'm not extremely interested in staying cutting edge at the moment, I stopped using epic gems, stopped min/maxing my gear to the T, and more or less set up a gearset that makes sense but isn't complicated at all. This conversation also brings itself into a full realization of our priority rotation as well.
Here's how I'm gearing for Ret:
Hit to cap(8%), Expertise to cap (which is actually 23, NOT 26-this was confirmed by a blue and you can google "ret expertise cap 4.0.1" to find ample evidence) STR, Haste to a flowing rotation (More on this later), Crit (this is about equal with haste, with the flowing haste in mind), mastery (mastery does not compare to anything else and can cause problems).
That's really about it. I find it much easier to keep these guidelines in mind when I'm reforging all my gear and gemming is still pretty much +STR (following the guidelines above). Enchanting is still the exact same as before and isn't hard to logically reason out.
The discussion of haste flow- The goal of haste currently is to get (the amount changes depending on your lag, if you are playing with a larger amount of lag you'll need less haste) your CS to time itself with every other ability. You want to be able to hit CS after everything else you hit. This allows you to maximize your HoPo gains while never having downtime in your rotation. If you are adding an extra ability between CS and something else, it means you are missing out on HoPo gains and will be able to TV less during a fight (which means less overall dmg). If you have too much haste and your CS is coming off CD while the GCD is running from your "off-CS" ability then you just wasted the time when you could be gaining HoPo (less TV, less dmg, less crits, less big recount numbers, less epeen).
I usually play with ~100-200ms in lag. This is apparently much better than most people get, and may explain why I don't find many movement fights difficult at all... But that's a different story. I currently can't get enough haste to even this out- yet. I end up waiting about .25-.4 seconds waiting for my CS to come off CD (which is still a DPS gain than not using it). Granted, this is an ideal rotation, and one I don't see a whole ton of (with the exception of fights like Marrow p1, LK p1... etc), and if you are waiting for your CS to come off CD, but have a moving enemy or you have limited time left, you are better off putting in an extra ability than nothing (I usually would save an Exo proc and Judge for sindy so when she took off on flight phases to tag her with both for the extra dmg).
Anyway, ~100ms, my 700 haste isn't enough. I'll update this with the true total, but I believe I'm looking at like 1100 as my exact number, while if you are playing with more lag you will need less haste.
EDIT: My current haste is 704.
Patch 7.3.5 Tomorrow
3 days ago