Mind sharing the type / model of that "24 display?
In my experience, some screens (Samsung and Philips in particular) are loosing quality when rotated - This may not be the screen's fault but NVidia or the open-source video driver I have used.
Re:Ask HN: What's Your MacBook* Desk Setup
by jasonabate on Sunday June 02, 2013 @11:46PM
(#5811249)
Same here, have had really bad experience with Samsung displays when rotated to portrait mode. Currently, we have a number of Dell Ultrasharp models (23" and 24" mostly), all of which look good in either orientation. They cost a bit more, but the quality is definitely worth it.
You can tell from the picture that it's a Dell. Probably a U2410.
Very basic: I do all my work on the MacBook (I love the Retina display) but have a browser with devtools open on an external 24" display in portrait mode.