Is The Sims 2 Open for Business any good?

This is a matter of opinion between players. Some like it, some don't.

Open for Business adds a lot of new content and playing concepts to the original Sims 2 game. I mean A LOT! You can virtually create any type of business you want and sell any kind of items or services from your business. You can run a home business, or purchase a business lot to run your business. You can hire new employees, set their work schedule, hire a manager (if you want to just be the owner who makes all the money), fire employees, and so on. You can interact with the customers and try to win over the sale from them. It costs quite a bit of money to start a business in Open for Business, just as it does in real life.

Some players feel that it is too difficult to get a business started and be successful (reach business level/rating of 10). Others find it quite easy once they get the hang of it.

It depends whether you would find it interesting to have your Sims run their own businesses.