Virtual cockpits in FS have gone a long way, and in addons for FS9 and FSX they can be fully clickable and almost photorealistic, suffering only from the bad light technique of FS which makes them appear to be too dark if the sun is not behind you.
For illustration, check the 3D cockpit screenshots of my favourite small-size airplane in FS9 here:
http://www.digital-aviation.de/crjsite/l_html/media_pa31_01.html
In fact some developers do not even incorporate 2D cockpits anymore, RealAir for example. their instruments are sharp, smooth and crispy, their 3D cockpits almost like 3D-photos.
and a video "TrackIR explained":
In how far it is valuable for dogfighting: a demo from Lock On:
Be advised that you should not expect the same ammount of visual details in Falcon's virtual cockpit.
relevance for racing sims:
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However, good racing sims (I use GTR2) offer functions that imitate dynamic head movement into the inside direction of a turn, so here TrackIR are not that much needed as long as you do not use to race door to door with the pack - but then it might come handy.
A commercial:
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