Something to keep in mind that a lot of simmers (DCS specifically) don't get when they want to jump into VR:
Once you hit the advanced 3rd Gen or any 4th Gen fighter or attack aircraft (essentially anything where you go "heads down" for any significant portion of the aircrafts mission profile) VR becomes more of a liability than an asset.
For those aircraft being a pilot is secondary to being a systems operator.
Think of an F-14; you have the front seat who would want to be in VR because they fly the aircraft, but the RIO would NOT want to be because they have very little need to be, especially since it makes interfacing with their mission systems so much harder. AH-64's are the same split.
Now if you are the sole person in the aircraft and need to do both missions being able to operate the systems fluently and smoothly via dedicated interfaces FAR exceeds any benefit from being in VR.
I've done it all, and I far prefer flying in VR. But for accomplishing complex mission profiles multiscreen with each being an MFD and a rich control set far beat that immersion.
Perhaps the best mix is using a curved UW and trackir plus dedicated MFD screens. Once you get that setup its amazing for that advanced capability set.
All of this assumes you want to use the full capability set of an airframe, or use an attack profile at all. If all you want is to use them for A2A, then VR is wonderful as long as you have a full HOTAS set, understand the preset modes on everything, and memorize the controls and alternate control schemes properly for BVR to close in conversion, countermeasures, etc.