Definitely. A properly fed, well trained JRT is a wonderful dog, and lots of fun to be around.
A JRT eating a corn based kibble, with little to no training, is so hyper it never stops moving.
My JRT, Emma, has been a hugely hard dog to deal with, in so many ways. I love her more than anything, and I'd do anything for her. She's incredibly good. She's sweet, she's obedient, she's cuter than most anything else. She's a great dog. She was a *horrible* puppy. I struggled so much to gain control of her. I finally stumbled across a clicker, and was told about positive reinforcement training, and her issues almost completely resolved. She's a VERY good dog, but it was a long time coming. She's hard headed, and she never stops. She's full of energy and spunk, and keeps me entertained, constantly. She's incredible with other dogs, but she can't be around kids, at all.
Of course, every dog is different, but.... JRT are very intense dogs. You don't really know how their personality and drive will be, until they're about a year and a half to two years old. They really are great dogs, but only if you're willing to devote a lot of time and energy to training them and keeping them entertained.
Amanda & Bevo 2015
Libby's Monkey N The Middle, CGC, RAE, BN, CD (Bean, Chinese Crested, 1/26/08)
Fluffy, Cairn Terrier, gotcha 6/10
Gaea's Pandemonium By Request (Chaos, Chinese Crested, 2/14/12)
Mischief N Miracles, RAE, CGC, #1 Parson Russell Terrier in AKC Rally, 2009 (Emma, 10/13/03-1/8/10)
Jewel, Italian Greyhound, 9/15/01-7/7/12