I agree with seadog - save your money and just fly coach - 3 hours is nothing for a flight. First class is much better for the longer flights, especially like our 14 hour flight from DC to Beijing - first class was awesome!!
But like they said, if it's legroom you need, go with coach-plus or get the exit row.
Travel Agent/Cruise Specialist w/13 yrs exp and 48 Cruises on 11 cruise lines! Favorites: Paul Gauguin - Tahiti: Uniworld River Cruises - Europe; Celebrity Solstice-class ships; Holland America - 12-nights Baltics & Russia; RCCL - 14-nights Greek Isles, Turkey, & Croatia; Holland America - 14-day Alaskan cruisetour; 10-night Canada/New England cruise; 21 days Hawaii w/7-night NCL cruise; Oceania - 25 days in Asia; more than 3 months touring Europe by train. And many all-inclusive resorts!