I have a 12 month non-compete in my contract - but I'm currently trying to get it sunsetted as the situation has changed since I agreed to it. In general the narrower it is the more enforceable it is - if it's broad then you can argue that it prevents you using your skills and experience to earn a living, if it's narrow the company can argue it is a reasonable safe-guard of their intellectual property, trade secrets and customer relationships.

The big question is whether you should disclose the existence of the non-compete to a prospective employer it might effect. If you don't and your old employer decide they think you are in breach, your new employer may not be happy with you. If you do disclose it, they may decide they don't want to take the risk.