JB sent an upgrade kit to me for testing because he knows that I will give an honest evaluation and he is confident it will be a good one.
Forget boot clearance issues. They are no longer a consideration.
There is only one potential problem due to manufacturing tolerances (Mazda's) and it is easily corrected if it impacts you.
When I installed the plate with the upgrade (I had been running my own Rotus mod) I noticed that second gear did not feel right. It made it into gear, but the throw was off somehow, like it wasn't moving as far as fourth and sixth. I checked under the hood and it turned out that the arm that moves you from one slot to the other was contacting the plate in second gear. I took a prybar (read large screwdriver) and bent it a quarter of an inch towards the driver's fenderwell and presto, it was like a new shifter. The thing is flat out awesome. Now I understand why some people rave about this plate and some are like, "yeah it works, but...". If you bought one and took it out, do yourself a favor, get the upgrade kit, bend that arm just a little bit like I did and you will fall in love with this mod the way everyone else has.