I'd seriously consider the Rift. I play 2D when I need to grind out a trade or if I need to multitask (read email/surf the web), but the Rift is a completely different mode of gameplay and can't really be compared to a flat screen experience. You do need a powerful GPU, and you have to switch to bottled beer (can't drink cans with the headset on). But the game is simply more fun in VR.
I've been a major proponent of multi-monitor gaming for over a decade. I had dual 21" Sony CRT's back when they weighed more than the desk. Up until two years ago, I was running a three monitor (19"/22"/19") apparatus on a HumanScale triple mount. I use a similar configuration in my office at work.
I spanned any game that could support it; simulators were the best (LFS, DCS, X-Plane, Prepar3D). Combined with TrackIR, I feel like I had a superior setup. Flight simulators were great because I could display instruments or side views on the peripheral screens. Other games, I'd have maps, spreadsheets or supporting documents on the sides. Sometimes just a web browser or email.
Even with a powerful system, some games were overload for my GPU and some had such poor support that it wasn't an optimal experience. Sometimes I felt it was a hassle just to get games to run well on a 4210x1024 display. I'm not surprised that many point to performance and interface as a VR-specific problem, but these considerations will affect any high immersion gaming experience.
Since getting my Rift DK1 in '13, I began to lose interest in spanning the game window across multiple screens. Yes, the larger FOV or better situational awareness was still a perk, but the experience wasn't comparatively much more immersive -- or fun -- than on a single rectangle screen.
The truth is I had entered a transitional period that most gamers will experience in the coming decade.
I now have a single 22" monitor and a DK2. If the game can do VR, I do VR. I don't bother with spanning or multi-screen anymore because it really adds so little to the experience in comparison. Why fuss with a 120° wide rectangle when you can literally wear the universe?
If you were an early adopter to multi-screen gaming (and I think even today it remains a niche that lacks attention), you'll be right at home with a DK2. You are already the type of person who can adapt your play style to achieve a next-generation experience. The hardware and software will get better with time. With ED, the software implementation is excellent. Once you do go, you won't want to go back.
If you prefer to wait a few years before evaluating new gear, then ED will be pretty good on 3 screens. Just like processors and peripherals, VR will improve incrementally as the years pass. You can decide when you want to participate.
One major compromise is that with VR you are physically committed to the game. You can't look away. You can't read or write notes. You have to know the game well enough to be able to pilot a starship without referring to spreadsheets or websites. The galaxy map kind of sucks in VR. Also, my face gets tired after wearing the Rift for more than a couple of hours. If you are the type of gamer who can't take breaks, the headset will take a toll.
Image resolution is a compromise. The game certainly looks sharp on a rectangle screen at high res. You can read text more easily and even visually identify distant objects better in some cases. But I feel that in VR there is something about being in the pilot's seat with the windshield and galaxy wrapping around you that is simply beautiful. You see through pixels and polygons and the game becomes a form of visual art.
For ED and other games this complex, I find that it's easier to learn on the old rectangle screen first. It's easier to access help and research commodities via web browser. A few weeks in, I find that I am still learning better when in 2D.
But I play better in VR.
