Dell U2312HM or Dell S2340L ?
Keep in mind that the Ultrasharp has a matte film and the new S-series model is glossy and has glass over it.
While the glass and glossy look nice and give the perception of better contrast, I'll choose the matte over it when actually working on it. Nothing strains the eyes more than glare, plus glossy surfaces show fingerprints and smudges a lot easier.
the S series does have a little bit thinner bezel. People who use multiple displays might like that.