Obviously everyone has their reasons on whether or not to use the C Class commute or take the $2,000. I commute to the U.S. and always take the C Class.
1. Remember that you are not really getting $2,000 when you factor in income taxes and the price of purchasing the ZED ticket.
2. How much is not having to worry about loads, cancellation, etc. worth? For me $2,000 is not worth it. I enjoy knowing that I have a confirmed ticket and never have to worry about getting to/from work. My flight is also 12-14 hours so the business class seat is important to me.
3. The best part for me is the frequent flier miles. Obviously each airline program is different but for the airline I commute on I generally get around 800,000 miles a year. If you like to travel frequently then the miles are nice.