Class is the word, but there is a large portion of the Boston crowd (and most English crowds) that won't warm to him because he's not an "all action" sort of player, ie he doesn't throw himself into tackles and chase lost causes.
Armstrong often lacked the strength to even get the ball in the air when crossing. We saw Junior play a few good longer passes today as well as his usual short passes and flicks, and he is strong enough to hold men off.
The main problem for him could be the travelling - it's a long trip to most Conference North grounds from London.