I have a copy of Kali on an HP Mini around here some place(i think its in the bedroom somewhere(hasn't been charged in about 8 months))... it use to come in handy but I haven't really even wanted to use it in months...I haven't tried parrot yet. But there was a copy of it on the coverdisc for a recent edition of Linux User and Developer. So I might boot from DVD and take a look at it at some point.
But I always have a copy of Kali knocking about on a USB drive somewhere. I don't have much call to use it, but it has come in handy a few times!