Thanks a million for all the great feedback guys. I made it out to the range today finally, even though the rain had the I40 W at a near standstill. Glad I did too as I was pretty stoked about the results with the affordable combo I posted about originally. I knew my BUIS were zeroed so I started by cowitnessing the SightMark at 25 yds with the bipod. That was super easy to do because the mount/dot were already dead nuts left to right and I just had to change the elevation a few clicks. I do get a little bit of dot flare if my cheek weld & eye relief aren't exactly right every time, but generally I can deal with the dot resolution. There are 4 reticule styles on the selector - thus far I've gone with the dot, but after hearing you guys' experience I'll try the outer ring or crosshair.
Then I played around comparing magnified and unmagnified shot groups at 50 yds. I hear you loud & clear Bravo re: the efficacy of magnifying a dot that's already covering X inches at Y yds. Doesn't make a whole lot of sense at longer range. But I clearly shoot better in the 25-75 yd range when it's magnified. (see photo) The left is just the SightMark dot @ 50 yds. The right is SightMark plus Vortex 3T @ same. Keep in mind that I'm not an excellent shot, so the 3.5" group on the right is pretty good shooting for me, especially just breaking these in. Only problem I had all day was the Vortex mount screws worked loose pretty quickly, but I still need to loctite those. That... and dudes kept asking me if my EOTech was mounted backwards.