For starters, I am CRAZY about Mint KDE CE. I got exposed to KDE while playing with PCLOS, but aside from the desktop environment, most everything else about PCLOS, though decent, made me miss my Mint (still safely installed on another partition). So, I replaced PCLOS with Mint KDE, and couldn't be more pleased.
One error, though an Ubuntu rather than a Mint error, is that when I edit a file as sudo (or open an application as sudo), the terminal reports the error ___ owned by uid 1000 instead of uid 0 several times, with a line for each of three files (which I represent just with "___"). This is a known Ubuntu bug. Unfortunately, when I tried the suggested fix (installing kdesudo), a slightly less annoying bug replaced it: Now, kdesudo reports "kdecore (KProcess): WARNING: _attachPty() 11." While this bug is also known, there's no suggested fix.
I'm not so much asking for a fix (though I certainly wouldn't turn my nose up at one), but simply reporting my experience, so that other Mint KDE users know it's not just them.