D800 - 20mm or just go for 14mm?

Just a quick question. Do you consider it worthwhile having a 20mm as well as a 24mm lens which I currently own? The perspective should still be quite obviously different right? The 24 I have I won't be selling but want to go wider. (not interested in the 14-24)

I'm considering just leaving the 20mm and going for the samyang / rokinon 14mm 2.8!