Actually I would like to go to a current Mac (no matter if Macbook or Mac Mini or iMac) - there various restrictions keep me from doing so.
Currently I'm using a 2012 Mac Mini (with 2.3 GHz Core i7 quad-core processor, 8 GB RAM and 250 GB SSD) and a 13″ Macbook Air with 1.8 GHz Core i5, 8 GB RAM and 128 GB SSD from the same year. Now Apple has introduced a new iMac: 4k retina display, 3.1GHz Quadcore Core i5, 8GB RAM and several large hard drives. Actually a very exciting device - actually.
An essential requirement for me: I want to use iMac as an external display as well - which is theoretically possible, provided you use a PC that has a Thunderbolt output. The problem: neither Nvidia nor AMD offer a suitable graphics card. So the option to buy one of the new Retina iMacs as a replacement for the Mac Mini is not available.
So I thought about variant B: changing the guard for the Macbook Air - the problem: although there is a new interpretation with the Macbook 12. But: with a Core M processor, it's not really an upgrade to the 1.8 GHz Core i5, the connectivity is also not available with a single USB-C port. As an alternative, the Macbook Pro 13″ Retina. This model comes closest to my requirements, but hasn't yet been upgraded to the current Skylake CPU generation. Also, according to my research so far, it is not possible to operate both the internal display and an external 4k display with full resolution without any restrictions.
I would like to make the leap into the world of retina displays - both on the desk and on the notebook. Unfortunately, this is - at least with Apple - still fraught with some hurdles. Neither the option of using an iMac as an external display on a PC nor connecting a Mac to an external 4k display seems to work satisfactorily. More information about the new iMacs with Retina Display can be found at heise.de.