Offshoring Developers w/ trusted employee advice?

Hey guys, a friend of mine who owns a small web marketing agency (around 10 people) wants to offshore to help speed up his scale, how's your experience with offshore as a small company?

His situation is:
- Ideally to increase capacity by offshore to India several developers (help w/ either internal or client work as lately the current team is almost full capacity all the time)
- Helps with timezone, since clients are international
- If he can establish in India, he can scale up faster
- There's also a 4 year long senior developer that is willing to go and help start the business in India as the "champion" for the offshore project and partners with him to open the branch in India, and my friend mention he have been one of the most proactive in the company

I mention that it seems to be all good if there's someone internal who knows the in-and-outs of the company, and as long as he can trust that the employee will actually do his job while managing, and also getting all the hidden cost clear as well as involved in recruiting the India team as well, but is there anything that might be missing?

I always hear bad experience with offshoring due to just the hidden cost of it, and the performance hit, but would having someone that knows the business starts the branch helps reduce that risk?