I’d agree with you in general SoM, but the OP has posted that the difference came about only as a result of using the boom stand instead of the tripod. He mentions no other setup changes. There may be some small differences in mic placement, but by the same token that one can argue that stand vs tripod cannot make 'dramatic' differences, so one can argue that small differences in mic placement cannot either. The OP describes the difference as 'dramatic' and this is of course an entirely subjective term and I would normally raise an eyebrow at it too. But when he also says that in the prior calibration he needed subtitles to understand certain dialogue and now he does not, then I'd say that this falls into the 'dramatic difference' camp
It is possible that the tripod was being badly used - indeed this is the main problem with using a tripod: it is not designed for the purpose under discussion so misuse is easy. And it is possible that the boom mic stand can be misused too, but it less likely to be so. And because a mic stand has been designed to hold a mic, its designers have taken steps to ensure that it does this without introducing problems caused by vibrations, mic mounting and so on. For this reason, all boom stands are essentially similar in design and do not have huge, thick legs like some tripods do, or large reflective heads under the mic, like some tripods do. I can change a tyre on my road bike using two spoons. Usually this would work. Sometimes it will rip the inner tube. A set of tyre levers costs next to nothing and gives a perfect result every time. Why would I defend the use of spoons? Yes, they can do the job. After a fashion. Ans imperfectly sometimes. But really...
It seems, as as often been so in the case of some members' recent posts, that a large mountain is being made out of a very small molehill. The only sensible advice is that one should always use a mic stand for best results if possible. A tripod can be a useful makeshift device but it is not the proper device to use. By using a mic stand one eliminates yet another variable and this can only be good.
And, for most of us, they cost 20 bucks! What is there to even discuss, really?
Ok! I'll byte I ordered a boom mic stand and the attachment as well and I'll post my findings when I run my calibration again, being I have what I consider a good one this should be interesting, and to be completely honest I have sever case of the "tweaks "and I hear its spread like wild fire through the Audyssey thread but its to late for me save yourself Besides my OCD wont leave me alone