I've got one - he is great.
I've never liked little dogs, but somehow he doesn't feel like one - must be all that personality! Caught his first rat at under 12 months, but he is just as happy catching a shrew or butterfly!
He needs lots of exercise & would consume his own weight in food if allowed!
Got him at 8 weeks, he's about 18 months now. Get's one very well with all other dogs, but is definitely the boss over the lab. Never had a problem with our chickens, ducks, sheep etc, but I spent a lot of time with him from day 1, loose with all the animals showing him what was expected.
Loves to hunt so you need to get a good recall instilled. Tecwyn will come running at my whistle even from 2 fields away & I can call him off mid chase, but it has taken time & effort to get there. I haven't taught him anything else apart from leave it, but he is very trainable.
After talking to the breeder at length we purposely picked a more submissive pup as this is my first terrier. It has worked for us, so far.
He is the most loyal little chap & wants to stick by my side, even more so that the lab. Highly recommend, for the right home.