<<...The darn AAAA battery compartment in the pen.. does it use a SPRING as one of the contacts?...>> Maraud: Yes. The spring is a reasonable length and should adequately compensate for the length difference. <<...Why are you guys talking about the HTC Flyer's pen in the thread ...Is it a compatible replacement.. does it use NORMAL batteries?...>> ...First of all, please do your homework. An hour or so of reading will fill in many gaps for you. Having said that, Yes, the HTC Flyer pen is a compatible, if expensive, alternate pen for the Q550. Some of us think that it is slightly quieter in use, and it has a second button that allows erasing in compatible applications like Journal and OneNote. It uses a AAAA battery just like all the other N-trig digital pencils... <<...I read that the touch screen isn't that responsive to touch, is it only the first touch after the touch screen is idle that is not responsive, or is the touch response generally slightly slower than other touch screen solutions?..>> ...We're slowly getting a handle on this. In one-on-one tests, the Q appears to be just as responsive as, say, the HP Slate 500. But subjectively, it somehow seems a bit laggy (with factory settings). By making a few adjustments... detailed elsewhere in this thread... my Q is now well within an acceptable range of responsiveness. It's going to take some time for the community to zero in on this, but it looks very promising.