By the way what problems does a RC network reset cause
A supervisor hold a solid reset state and switches rapidly to the opposite state when the reset expires. On the contrary a RC circuit slowly (in electronic terms) glides from one state to the other.

Logic circuits are unstable and may oscillate when an input is in the grey range between max Vil and min Vih.
Some chips have lost the flash, some have lost the ISP and other 'accidents' have been caused by RC reset. In the olden days (when the king of diamonds were still a jack) there was no ISP and memory was fixed or UV erasable RC circuits usually did quite well, but, fortunately, we have past that stage.

Another problem with RC circuits is that they do not react to rapid fluctuations and slight droops.

This will do, if you want more, the last issue of Maxims Engineering Journal has a multipage article of the unpleasantness of RC circuits.

Erik