Some advice for lenses for NX11 please

Hi All

I currently have the NX11 with 18-55mm zoom. I am considering purchasing the 20mm lens but I would like to know if the increase in overall resolution/sharpness is actually noticeable in real terms.

I appreciate that their is a distinct advantage in size, and when looking back over my shooting history most of my shots are in the 18-2xmm range so the 20mm wins in that respect, but resolution is an important factor for me.

I would please like to hear from anybody that has done actual comparisons between these two lenses and I would very much appreciate any input that you can offer.

Many thanks.

--
A bit of fun. Our boys: http://www.youtube.com/watch?v=TepUqyf2rsk