So I decided to go in for a second opinion at True Spec, I felt a bit more comfortable with this one--we took our time more and it was less rushed and we tried out more options.
(1) The fitter agreed I needed a heavier shaft (120g) but said a stiff flex was better with my swing speeds (83-86 mph with a 6 iron) than an extra stiff flex, which was my intuition as well. I hit the extra stiff fine, although not nearly as far as the stiff, 168 carry versus 178 carry. My fitter said that the stiff was better than the extra stiff because it produced a better/higher launch angle, 16.9 versus 20, and higher flight which also makes sense to me. Probably easier to hold a green. One big oddity is that my spin numbers were radically different on the Foresight machine versus the Trackman, which may have contributed to the different shafts (the Club Champion fitter put me in extra stiff in part to reduce what the fitter thought was excessive spin). I normally take lessons on trackman anyway, and my coach has told me that trackman often has inflated spin rates (he even puts little stickers on the ball to get more accurate readings of my spin), so I wonder if the Foresight gave me the more accurate reading over the Trackman, but of course I have no way of knowing for sure. Kind of frustrating not knowing which technology to trust. In the end, think I will probably go with the stiff flex over the extra stiff, but wanted to see what people on here thought.
(2) The fitter also recommended I get the Apex. I hit some more game improvement clubs as well as the Apex. I hit the Mavrik irons pretty well, my best smash factor and distance, but my fitter said that he preferred the Apex because the Mavrik launched lower (18.7 versus 20) and had a lower ball flight, although it doesn't look like a huge difference. The other thing with the Mavrik was that the offset meant that my most common miss (a hook) was more severe than with the Apex because it gave me more time to close the club face, which is not something I necessarily want with my more closed-face swing. The Mavrik seemed a bit more forgiving, I felt like I had some mishits off the toe that went about 10-15 yards further than similar mishits on the Apex. And I hit the Mavrik a little bit further, although I looked up the lofts and the Mavrik 6 iron loft is basically equivalent to the Apex 5 iron loft, so I think the extra distance may be a bit deceptive. I'm still a little torn, but I think I'm leaning more toward the Apex over the Mavrik, in large part because I seemed more consistent with the Apex especially when it comes to left-right consistency, but I'm not entirely sure as I hit the Mavrik further and had a better smash factor.
(3) At Club Champion, they had me hit once to figure out my lie and said I was standard. At True Spec, it looks like their machine records my lie on every hit, and it has me pretty consistently toe down to a substantial degree. The fitter said he would recommend fitting me with more upright clubs as a result. I'm a little torn on what to do. I'm more tempted to fix the lie angle through lessons rather than bending the club and so just buy a standard lie, but I wanted to get people's opinion. Also, I did some research and saw that you can bend clubs after you buy anyway so it might not be a big deal to buy standard now and get them bent later. Is there any downside to bending clubs after the fact as opposed to buying them more upright directly from the manufacturer?
(4) Also, per Adam's advice, I asked about grip size and he confirmed that I was definitely a midsize grip, so thank you so much for that advice Adam. I made sure he was very sure about that being the proper grip size and tested it a few times and it does seem like midsize is the appropriate grip for me.
Thanks in advance for any help!