I second the motion that DM's Comet 4 series is excellent - also in FSX - there are notes with the model on how to adjust the config to optimise certain aspects for FSX - or you could check out their forum at CBFS, where it has been discussed.

Don't forget that it was from the Comet 4 that the excellent Nimrod was forged - and Simshed have released an excellent freeware version recently.

JD