Oct 18: the increase of 12 stitches, 6 on either side worked well to open up the arm hole area. The fit is perfect.
I made a mistake with the 3needle bind-off with the result that you can see the seam, but that does not bother me or let’s say that I am too lazy to correct it. I like the result overall.

Oct 06 2009: I tried it on before I bound off the stitches and it seems that the sleeve opening is too tight. I will go back to the waist and after the initial 16 st decrease, I will increase by 12 st to widen the sleeve opening.

I was making progress at a rather fast pace. The design of this top is great. You knit in the round until you reach the sleeve part, you place 10 stitches on either side of the shirt on hold, then you cast-on and knit the first few rows of each sleeve separately and after picking up the body again, you just knit the sleeves into the round and begin with the raglan decrease.
The only change that I made, was to knit the body part about 5cm (2inches) longer.