I have H2O and I needed in one instance to use reset button (long pressing power button didn't helped
).
But, from people reviews I didn't heard that KA1 has dedicated reset button and this is a bit of a problem for their owners.
In my case, I had faulty book, that works on my PC (SumatraPDF reader), but for some reason "blows" koreader and cool reader. I wrote about this before. So I think that dedicated reset button can be handy, you never know when you might need it.