Yes Dude, slow to react and requiring to much pressure on them to stop for our riding styles.
I had them in my younger sons 400 after he had passed his test and was still on the restricted licence and he did not like them, I gave him the 600 to take for a spin as a bonus for passing his test and the first thing he asked when he came back was how come the feel and reaction on my brakes was so much better better than his and was wondering if it was due to the difference between the 400 having Brembo and the 600 having Yamaha calipers. I did not think so, but knew from my own experience it was most likely the pads, anyhow we changed the pads shortly aftwards to HH type and he was delighted with them and asked to change the rear ones to HH also.
Not normally recommended for the rear of the 400 or 600, but we both prefer the feel of the HH on the rear also.
However every one to their own taste and I know a few friends who have always used organic pads.