Keep him for sure. Give him some freedom to work on his side projects during working hours.
Not only will he appreciate this, but it will send a positive message to the other 50 who are wondering if they will have an interesting career or if they should be passive looking for other opportunities.
Not only will he appreciate this, but it will send a positive message to the other 50 who are wondering if they will have an interesting career or if they should be passive looking for other opportunities.