I haven't noticed that but I'll play around more and see if I experience the same thing.
Ok, I think I found out the problem. It's not the sensitivity of the Instrument 1 but the Kontakt player. I thought I was going crazy because I actually came to the conclusion that my Instrument 1 was faulty and it is not sending out different velocity at all (ie, it's either on / off). What reinforced my suspicion was that when I looked at the volume meter at the Kontakt player, it's either on (all at similar level), or nothing.
I ended up borrowing my son's iPhone and tried the official app. And my Instrument 1 worked perfectly. Light touch trigger much lower volume and different timbre than stronger touch.
I think that I just need to spend more time with Kontakt to fine tune the instrument.
Toys Samurai
Ok, I am totally new, and I need to make sure that I am not imagining things, but it seems that the sensitity of the fretted mode is not the same as the pad mode. For example, I found that even the high sensitivity of the pad mode is not as strong as the medium of the fretted mode. I played a simple C-chord in the fretted mode at medium and a fast light strum across the bridge would trigger all 6 "strings" w/o problem. On the other hand, in the pad mode, it often missed a string or two even when I slowed down and strummed harder.
The problem is, there's no easy way to verify if I am just bad at playing the instrument.