Isuppose it depends on three factors: what your resources/talents are; what stage you are at and what you want to achieve. If you have limited resources and prospects - you are far better off being hte big fish in the small pond. If you are starting out - as long as there is a well trained teacher in your area you would do better to stay with them initially before making any moves. however, as you advance in any art form almost everyone (theres always the genius exception
) needs to move to where the training is going to take them to the next level. You see it with the young stars: they start with local coaches, move to national ones and eventually they have to seek international training. By the time you are a pro you may travel between continents for your regular training lesson. The last factor is whet you want to achieve, and I think that speaks for itself from the above.