Pros
You get to be in a game store every single day, spending time with variety of interesting people who all share a passion. You develop a relationship with your customers, which can be very rewarding. You have a huge degree of independence, if not autonomy, and the operational support is pretty darn good. You get to teach people fun things, and generally create a fun environment for people to enjoy. There are a lot of smiles to be had at Games Workshop. Because you run a single-person store, every one of your accomplishments is undoubtedly YOUR accomplishment, and you do get recognized for them. The benefits are also excellent, and the employee discount is fantastic. A typical hobbyist will save literally thousands of dollars by getting a job with Games Workshop.
Cons
You are trained to have some contempt for the opinions of those same customers with whom it is so rewarding to develop a relationship. The job description, at the time of my employment, was "to deliver sales growth by performing the Retail Standards." The Retail standards were (are?) 20 axioms whose wording did not change, but whose definition developed further every three months or so. That means that the only thing that stays constant in your job description is the expectation that your store will make more money than it did at the same time last year. If you do that fantastically for two years and then fail to do it in the third, the first two years don't matter any more, even if you are performing the Retail Standards. In short, your numbers matter more than anything else. Because of this, there was relatively high turnover. You only see your fellow store operators at training camps every three months, and many of them don't last longer than two training camps (six months). Turnover was pretty high when I was there, and that has a negative impact on morale, even if everyone wants to put on a happy face. You will not be paid in proportion to the effort that you put in. It is a LOT of work to run a successful hobby center.