I have prepared one of these cocoa sticks with my Senseo and was rather disappointed. The taste is indeed delicious but the machine remains an excessive amount of water standing on the pad, which I find rather annoying.
After I've made in a cup of "real" milk and hot in there done that powder, tastes better and is just as fast!
Conclusion: Milka should just bring cocoa powder in the trade! ;) The taste is in fact better than me!