I won't let it swing my judgement, but I find it difficult to play FS2 w/ TrackIR due to the limited cockpit support. A cockpit gives you a frame of reference that helps you judge situational awareness and sense of scale. We (I) didn't need it before TrackIR, but I'll be the first to admit that I've been spoiled. But, if it's as good as (or better than) FS2 or IW2 I'll be more than happy...
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"You know what the chain of command is? It's the chain I go get and beat you with 'til ya understand who's in ruttin' command here."
- Jayne Cobb, "Firefly"