I fly between DC to Manila several times a year and take numerous other long trips and have to say that flying in business often makes what is otherwise a 24 hour ordeal much more bearable.
In the past, I'd only fly business on someone else's dime, but now that I'm retired, I'm more inclined to fly business days (perhaps its an age thing) even if I have to pay myself. Some of my reasons:
First, international business itself has gotten a lot more luxurious over the past decade, and is now comparable to what first class used to be. Flatbed seats (with sumptuous bedding), private seat pods, 24 inch TVs, good food and wine, and (sometimes) solicitous service. Not to speak of access to international lounges (showers, food, drink, sometimes even beds), no lines, plenty of overhead space, first on/first off, special baggage handling, special check in, special security, etc.).
Second, virtually no one pays the "rack" rate for business class. Discounted coach tickets to Manila, often on full planes, typically go for $1500 - $2,000. But while Cathay and Singapore may ask $10,000 for business class round trip from DC to Manila, full price on Delta or United (and often Cathay and Sing too) is typically more like $5,000 to $6,000. And Ethiad and Emirates (flying the other way around) offer a wonderful business class (with a free stop and a night's hotel in the Middle East, if desired) for $2500 -3500. And, if you have frequent flyer miles you can do even better. Both United and Delta, for example, typically offer Business class upgrades for 25k miles and $500 each way over cheapest coach. (Not too speak of the deals offered by consolidators and mileage bucket shops, which I usually stay away from.)
Third, within Asia, good business classes are available on Singapore, Cathay, Thai and other airlines (not quite up to the transpacific and transatlantic standards, but much better than domestic U.S. business) that are sometimes heavily discounted. One time, for example, I was quoted $350 on Cathay for a coach round-trip from Manila to Beijing (not a bad price), but was offered Business Class seats for just five dollars more ( $355 roundtrip, a steal!!). And Singapore and Thai offer frequent flyer tickets within Asia for 25,000 miles round trip in coach, but only 35,000 miles in business...including a stop, if desired (e.g. Manila to Bali with a stop in Singapore or Manila to Rangoon with a stop in Bangkok!!!)
So, while I certainly won't pay $10,000 for business class, I was willing to pay $2600 for my next trip from Manila to the States in March (vs. $1500 in coach)....