I think you would be happy with either kite, and it depends on your own finances.
When I had the XR it was my favorite kite, and when I had the ESP bar it was my favorite bar (with a few minor mods).
The XR2 are a bit different but lovely. The XR2 has the awesome pump hose connector/the XR does not.
I used to love the ESP bar but I love the Sensor bar even more...so all around the new gear is a step forward. I have not done any mods to the Senspr bar because it is near perfection. The only minor complaint I have is with replacement of the centerline being a little more difficult. If you get the Sensor bar I advise waxing the shit out of the centerline to prolong life.
...but I kept my 11m XR (and one ESP bar as well) because I love that kite too much to sell it and know I would be more than happy to pull it out if my new 11m XR2 is grounded.
You might also want to look at the GTS2 kites, which are in every way on par with the XR2...but slightly different feel, but great performance if you like the modern C style. I want to get a small quiver of the GTS2 as well.