No, I don't think it should be up to the server host, because in the countless threads I've read on TrackIR usage in flight sims and FPSs, I've read not one complaint from non-TrackIR users about a perceived unfair advantage being wielded by those who do have a TrackIR.

Also, servers should be able to restrict monitor sizes. I refuse to compete against anyone with a screen larger than my iphone.

That's not why, it's because you own TrackIR yourself and thus am naturally biased because you feel it's your right to be able to use your tool on every server regardless of whether the host wants to or not.

Gradual leaning for example and gradual cover using TrackIR will give an unfair advantage for example, since it's very hard to do proper gradual leaning etc with a keyboard.

And, to the poster above me, you can't compare monitor size to TrackIR, TrackIR is a control-method, not a display-system.

And just an FYI, Full-Body Display in first-person has not been confirmed, it wasn't in Red Orchestra, and has not been confirmed for Red Orchestra 2, it's thus very possible that TrackIR will only be used for vehicles ala OFPDR, in which case I don't mind particularly much.