Help me choose my Windows 8 AIO

Having been a PC guy all my life laptops have never really appealed to me, i love sitting at a desk. However i love the amazing designs for transforming laptops/tablets revealed in the last few days. For me though the stunning AIO's that have been revealed recently are the perfect match. So i need some help choosing! I love the swivel down to almost flat form and being a designer i need something that can keep up graphically. Probably got a budget of around $2000.

1. Lenovo a720 - http://reviews.cnet.co.uk/desktops/lenovo-ideacentre-a720-review-50008446/ - Looks incredible!

2. Dell XPS One 27 - http://www.engadget.com/2012/08/30/dell-announces-xps-one-27-aio-running-w8/ - Have always used dells and i like the look of this.

3. http://www.engadget.com/2012/06/04/asus-transformer-aio/ - Quite like the option of running both Windows 8 and Android on a desktop but i reckon the specs will dissapoint...

4. HP Z1 - http://h41111.www4.hp.com/new_workstations/uk/en/z1_tech-specs.html#.UED2PdZlQas - Probably overkill for what i need and would stretch the budget but customization options are good!

What do you guys think? Which would you go for?