I have much experience with both.
I have an Obutto racing rig for iRacing and 3 x 27 inch triples that I loved. I got the DK2 at launch and I can honestly say I don't play any other games as they don't have rift support other than ED and iRacing. The sense of immersion is beyond real and so much easier to fly / drive around.
As said the resolution is not quite there yet, but you very soon forget about it and with a little bit of time in ED you know the menu commands anyway.
The only problem is that you are cut off from reallife and so keyboard / note taking is a pain, but manageable if you are set up right. I can peek down my rift and still see the keyboard when I want to and worst case, route planning, I just prep before or lift it up for a breather as well.
I use a Warthog Hotas, so this obviously helps with buttons and commands, but voice attack sorts most other things out.
Do you buy now or wait. Well are you the type of person that puts off new technology or embraces it ? Can you afford the £400 or so for it knowing it will last a year before the CV comes out and you may get a little money back on the DK2 on ebay ?? Only you can answer that. If money is tight, then wait for CV, but if it is between triple cripples or DK2, I know where my money would go.
Good luck mate, try and steal a go with one at a friends house ?