CodeIgniter For Commercial Purposes

[eluser]mcarroll[/eluser]
Greetings,

I am new to CodeIgniter, but I'm considering using it to build a commercial eBay like marketplace. Would you experienced CodeIgniters recommend using this framework in a large-scale commercial system? Or would you recommend a more mainstream commercial solution?

Some concerns I have in general include: security, scalability, and time to market. The little bit I've seen of CodeIgniter makes me think time to market would be very short, but the security and scalability are concerns for me with an open source, easy to learn/use framework.

Any advice, anecdotes, explanations would be appreciated.

Thanks.

Matt