Hi d, great perspective..totally respect your decision to keep the B10...have never used one, but have heard they are awesome blades..I will say though, the R9 is extremely comfortable in choke ups (for my hands), and does better than many smaller blades (both fixed and folder) I've had on slicing, and definitely... every other chopper I have used due to the edge geo, ergos on the choil, and sculpted micarta. I find the R9 the best all arounder that i've had so far, and frankly am content unless the Lord sends another my way.
The thing I love about Busse & Kin, is that I rarely here of someone moving out of the line to find a better performer..a particular blade might not meet their personal needs, but the quality etc keeps us looking for internal opportunities..

, which in your case, seems to be one of the most respected blades on the market.
Be well,
Bar