Can you pair a 5K iMac (27") with a regular 2560 x 1440p 27" external monitor? If so, is there any conflict with the two resolutions? Would they look unbalanced or different in any way in a dual monitor setup? I've never used a 5K monitor before, so I don't know how they look (i.e. size of text, icons, etc) or whether they are scalable. Thanks.