I've 4 jack russell, 2 little size and 2 parson type, from 3 different lines.
The best one's the little bitch on the pic. Too hard to hunt foxs but very involved with badgers. Unfortunately, she don't pass the qualities to its progeny, we tried twice.
My jacks vs my patts... Jacks are perhaps quicker, Patterdales are able to hunt longer. My Jacks are sometimes inconstant and my Patts lack a bit voice. Here the voice is very important because we hunt without collar.
But I'm very happy with these two breed, Some are marvelous workers.