Bottom line is (and I'm not an attorney) your employer would have to be able to substantiate damages from you changing companies.[/b] Courts/arbitrators typically don't look favorably on restricting someone's employment opportunities. Most companies know these things and won't pursue enforcing the contract.
This^
I work in sales in the Chemical industry. I am on a 2 year non-compete. I'm also at a senior enough level that I have had a hand in enforcing non-competes also.
I respect a persons right to work for anyone. What we're trying to prevent is someone coming in, getting to know trade secrets, and/or our major products/customers, and using that for themselves or at another company elsewhere. That happens all the time. Particularly in sales. A person comes in, does 3-4 years with a company, get's to know the customers, builds a relationship with them, and then leaves for a competitor and starts selling the same products to that same customer, for the competition.
I have no issues if an employee goes to sell the same product in a different market, or sells a different product to the same customers.
At least in the sales instance, the way to get around non-competes, is just to not compete. If you work for a competitor, then you can sell a different product line to the same customer, or the same product line, to a different customer base. Best if the new product line wasn't something that your previous company offered - that's not particularly difficult to do in the chemical industry.
I think you will find the law in most instances will require proof of damages. In these cases, we have to show that we lost specific business, with a specific customer.