I have had the TX apart and its power button switch is considerably sturdier than that of the TE which did have a poorly mounted switch. The problem it has is the plastic button (that which you press) does not line up well with the switch plunger. This and the fact that it is too short to reach the plunger without depressing it hard.
I put a small dab of JB-Weld epoxy on the part of the plastic button that contacts the switch and that solved that issue. My button works very well. Also, a single drop of WD40 applied to the switch (not the button that your finger presses) allows for a better electrical contact. I did this to my button and switch when it was fairly new and it is still working perfectly after over a years worth of dailey use.
It is too bad that Palm didn't get it right from the factory but it is a very solvable issue.