I've used Zyxel USG 100 for a small installation with Bluecoat and was pretty satisfied with it. The school is moving to 1 to 1 computing now and I am evaluating whether or not the 310 or 1000 will be sufficient for the increased load. We are a small private school with around 160 students K - 8 so we likely have lower bandwidth requirements than many others on here.