Why not get some opinion cards made up where everyone who runs all 4 machines can anonymously rate the predetermined characteristics of each machine and possibly vote on the favorite aspects of each machine.
Maybe an unbiased

panel of fifteen or twenty guys that can vote on a "Favorite" ..........NOT a "Winner".
Why is it that guys from NY are always able to come up with the most logical ways of doing something.
I like the "favorite" idea. I think they should be new out of the box, factory sealed. Run them on the same TM and porty. Forget tweaking, that's simply a personal preference. If the rotary has to be tweaked, then leave it at home. It should be, maybe a point system, based on (1) features including but not limited to speed control versus no speed control, stock out of the box (2) ease of use/feel (3) price/value (bang for the buck), (4) quality of construction and appearance. Any who evaluate have to evaluate (run) all three or four rotaries. Also, if there are different types of carpet they have to run all the rotaries on all of the different types of carpet. I think the biggest thing to measure, and I'm not sure how to do this accurately, is to somehow measure the amount of moisture left behind in the carpet by each rotary. The cards are filled out and put in a box. Mikey delegates who ever he deems appropriate to tally the results.
In the end, I think if a rotary is being produced and sold, than they are all winners based on that fact alone. The PCC's have different likes, budgets, challenges and circumstances that are peculiar to them. Choices is what it all comes down to. I'm in favor of the shoot out as a touch stone to lay to rest some of the myths that some propagate here.
FYI, I heard HM is redesigning the RX for release this Spring. (rumor) but I can see that happening. Updating the design that's 30 years old is reasonable. They have done great with what they have and have set a bar for the rest of us who are building rotaries.