I have put on order for a 23" Dell Ultrasharp U2312HM which is going to cost me £162.36 including delivery. However there has been a recent price drop in the 21.5" Dell Ultrasharp U2212HM which comes to £141.00 including delivery. Is there any discernible differences between them apart from size? If there isn't. Then in your opinion is it really worth £20 for an extra 1.5" inches.