I am considering buying Track IR and wonder if it has a negative impact on frame rates in FSX?

I never noticed any change in frame rates, I did notice a smoother movement compared to using the hat switch. I highly recommend TrackIR.

Same here. No change in FPS, and smoother than using the hat switch. Best hardware I ever bought for FS. Buy it, run, don't walk :-). It'll transform your FS experience!regardsGrahame

Thanks, guys... Will have it within the next week! Can't wait!! It's the only addon that I've heard ONLY GOOD THINGS about.