TechShop is great for hobbyists with some money to spare (there are a lot of hidden costs, both time and money, that they don't tell you about), but terrible for professionals. Their machines are regularly not working for days at a time, and I've had experience with multiple locations so this is indicative of the company as a whole.

If you want to manufacture with plastic, I'd be surprised if there was any reason to do it outside of China. If you're working with metal, it's a much trickier question.

Along with EMachineShop, there's also Plethora. I've never used Plethora and it seems incredibly limited, but they've been around a few years and have a ton of people on staff (which can't be cheap) so they must be getting decent business.