My monitor setup is an LG 34" Curved UWQHD, driven by a clocked GTX980 - and for VR I use a CV1 Rift.
I got the curved monitor as an upgrade with the GPU as I got my rig ready for E

.. loved every second of it; and by the time my oculus arrived, I wasn't sure that I would even make much use of it..
Couldn't have been more wrong. as others have said, it's the difference between playing a game where you control a spaceship, and actually sitting in one. When I switched to VR + HOTAS, it just transformed the game. flying around planets to find the solar limb just for the hell of it. VR is glorious.
Yes, there are issues with lower resolution, and sharpness of lines. But those are just not that important for the complete joy of being *in* a spaceship. the degree of immersion can be quit jarring. it's a common thing to look down at your own hands, and get startled when one of them moves (the little handflex the avatar does...). Because you so quickly adapt to those being your legs and your hands.
I was forced to go without my CV1 due to a fault that needed a warranty swap-out. I think I played E

twice in that time. it just felt pointless.
As for it being a different game - I think it is a subtle edge, but yes - UI issues in monitor play don't bother you as much, because you never lose track of the fact it's a game. They are more jarring in VR because you do lose the 'only a game' feeling.
Personally, I'd buy it again, no hesitation, even if a new Oculus was due out in the new year (I don't believe that's the case, just making an example) - because the price is worth the play time between now and then.
The next generation of this stuff will be mind blowing. I'm just accepting that means staying on the PC hardware upgrade ladder for a bit. worth every penny.