Join Date: Feb 2003
Location: Alexandria, VA - DCA/IAD
Programs: BA Gold, American Airlines, Marriott Plat, Hilton Diamond, IHG Diamond
Posts: 5,089
The thumbnail response is...
Coach will get you there and back. Nothing more, nothing less.
Business class will get you there and back with everything you need (space, decent meals, beverage service, in-flight entertainment, etc.) to be comfortable.
International First-Class is not only everything you need to be comfortable but also everything you want. Take what you need and then add a heavy dose of luxury.
Think of driving a roadtrip of 1,500 miles. Then think of driving that trip in a base-model Toyota Corolla, a well-equipped Honda Accord, or a fully loaded Mercedes S500. You get the idea...