A guess why this topic seems to go round & round is because it depends on factors unique to the individual, so it boils down pretty much to personal preference. Some of such factors include what one is used to as well as what one does mostly.
For me personally, 16:10 is preferred as I do so many different things/type projects (including movie viewing).
As such, there are other factors which, although not used often, are nice options to have such as portrait mode capability, built-in screen grid dispaly capabilities, various video mode types such as standard, adobe, user, scene, theater, etc.
For general across-the-board video work (eg, document viewing, photo & graphics jobs, making brochures & newsletters, making specialty audio/videos, light gaming, movie viewing, etc.) my monitor suits me outstanding and it would be hardship to give up. Fact is I should have two side by side.
One thing though that is hard to see how it is not PITA with 16:9 is when attempting to view webpages which employ a fixed banner heading below which content scrolls. It is perhaps not common, but when it happens then extra vertical real estate is greatly appreciated (at least by me).