Some varieties just don't produce well no matter where they're grown. Over the past 20 or so years and 20 or more varieties, I've gotten rid of the following: Hallertau, Tettnang, Saaz (and varieties related), Kent Golding, Willamette, Nuggett and a couple others. If one plant won't produce at least half-a-pound, they get yanked. A guy I gave some Hallertau cuttings to down near Pittsburgh had great success. Was it because he was a little South of me, or the fact that he had them growing in a floodplain? All you can do is try and make sure you give them at least 3-5 years before you decide to get rid of them. Grow On!
Nugget? I'm just north of NYC and my nugget plant used to produce quite a bit. It was only three years old when I moved. I tried to transplant it at the new house but it was one of the ones that didn't make it.