Hi Jason,
It can be very confusing to someone who doesn't know the difference, and I am sorry you are confused by my remarks.
Just to explain it a little more clearly.
At one time R8 used to be the domain of the larger industrial machines, but now it is starting to become the favoured fitting for home workshop mills as well.
It is nothing to do with how good each system is, as they both operate in the same way and have equal gripping power.
Where the R8 scores is when you come to break the taper to remove the tooling. MT3, with it having such a shallow and long taper can under certain conditions be very difficult to remove and then a hammer wack is usually required to free it off (I cast lead hammers specifically for doing the job, to prevent damage to the machine), whereas the R8 will release almost by looking at it.
So really it is nothing to worry about, it is just that if I had the choice, R8 would be the way I would go, purely to keep the blood pressure down.
I use both systems, R8 on the mill, and MT3 on the lathe, but I do have adapters to mount MT tapers into the mill, especially if I want to use large drills with an MT taper.
I hope this clears it up a little for you.
John