So, I had a chance to do a side by side with the brand new Takumi Micron that arrived yesterday, and my trusty daily driver, the CM-SB v2.
Did a number of tests with different reductions and paints, and various lines from large to ultra fine hairlines, flipping back and forth between them to get an apples to apples comparison.
I personally noticed a HUGE difference in control when it comes to accuracy and comfort. But that may have a lot to do with being very, very familiar with the SB and my painting style.
The Takumi "opens up" more slowly in a linear fashion more than the SB (new head and needle to be as fair as I could). The SB's opening is more sort of geometric, the takumi more linear. So when controlling various thicknesses on the fine side of things, I have far more control. It's definitely more responsive, more like a CM-C+, but without the annoying cup in the way. Also, the trigger is more natural and easier to use. It's hard to describe, but the pull is just smoother somehow. Some of that could be the age of my SB tho. It's been my workhorse, so there's some wear and tear there I am sure. But the pull on the Takumi is somehow just easier to tune.
The needle stop wheel is also much better IMHO. I almost never use it on the SB, because it is prone to drift and even has been known to fall off mid session if I actually use it, and it slowly drifts back. The redesigned needle stop is much better machined. No drift at all. So I might actually use it.
Also, even with the soft spring in the SB, somehow the takumi just feels easier to plunge down, so I get less hand fatigue. I put this down to the shorter front leading me to hold it slightly different maybe. In any event, it works for me.
I thought the bigger side cup would throw the balance off, but I can't say that I actually noticed.
Also, honestly my hairlines were darker, tighter and the paint seemed to just flow better. I went back and forth, sure that maybe it was a paint reduction change, or confirmation bias, but even when I went back later and looked again, the Takumi lines were richer and tighter. The air flow seems smoother for lack of better description. Pressure was between 15 to 22 psi on my tests.
Some other folk notice mostly the response, but for my use there are a lot of very minor changes that make it a comfortable delight to use.
Still love my SB, but I suspect that the SB will become my backup, and the Takumi my primary brush.
I suspect that how you perceive the changes will have everything to do with your hand size, and style of painting. But for a big guy like me, this is the micron with all the wish list changes I've had over the years. So much easier to use on a long session.
Very happy with this purchase.
However, I will say that you don't notice nearly as much difference at higher pressures or with larger lines. There they are pretty much exactly the same. So the differences really only count for ultra fine detail, or in the hands of someone super familiar with the SB that already has excellent control. If someone was just starting to use detail brushes, or used other brushes more often, I don't know that the differences would amount to very much. So if you're looking for a micron, and you can get a good deal on a used SB, they are about 90% identical. The differences only really would stand out to an experienced micron user that does a lot of detail work. So it might not be worth the upgrade.
If you are very familiar with the micron SB and do a lot of tight work... that extra 10% is all the difference in the world.
So, that's my two cents.