It was many reports like yours that gave me significant pause in purchasing
FSX, but it turns out my trepidation was unwarranted. I've turned all
display settings to High with a target frame rate of 20 and the worse
volatility I've noticed was a very momentary drop to 16 fps (press "shift-Z"
a few times to display your fps). That's not enough for me to have noticed
any "stutter".

On the Kiwi, with its 104" screen, 20 FPS is absolutely awful. Sadly,
I've seen FSX drop below that for a moment or two, so it's really not
usable in every flight regime.

I've found that 30 FPS is the minimum for realistic landings, and 50
FPS is the minimum for realistic formation flying. In FS9 I've got
the Kiwi "locked" at 55 FPS, which results in an absolutely perfect
rendition of flight, with instantaneous control input/reaction.

If I set the realism a bit lower in FSX, it is acceptable. This allows
us to fly the cool new aircraft and "missions", which are quite fun.
However, for realism, we'll be sticking to FS9 until Microsoft figures
out a way to make FSX run faster.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"