Duo v2 comparison and help please

Thanks PapaBear. Choices makes my brain ache, but think im getting somewhere in narrowing things down. :)
Think i read a comment somewhere about the latest gui version being 5.x.something... And that this was only on the newer product and not likely to be available n the v1. I may have got that wrong, its just one of the many snippets floating around in my brain that im attempting to condense into a purchase decison! While i probably havent established why exactly i want the new gui version except for the possibly naive assumption that newer equals better, its one of the threads im grabbing onto. I will research more to flesh out why it might be better and not available to older products.

But i do accept that Netgears long term support if worth valuing and the forums here all seem positive. Although just to add a slightly negative perspective the other netgear nas product Stora seems to have many complaints about support. I havent got to the bottom of whether its because they are all uber geeks stuck with a simple entry levl product or because its fundamentally flaky. The thing that disuaded me was needing to have access to the Netgear server over internet to set up and configure. Sorry, rambling off topic! Onwards with Google we go...