Have heard of Active Sky through this and a few other sources, would like to hear your praise or otherwise - your honest opinion - as to whether you would recommend purchasing this product.  I am specifically looking to improve thunderclouds as the default ones in FS2004 are a disappointment, compared to what I used to have with FS Sky World 2002.  There don't seem to be any alternatives out there, and upon studying the cloud source files in FS9, many are different file types that cannot even be opened for editing.  Many thanks -

...maybe it's just me, but I always preferred the clouds in FS 2002.
Much more realistic I reckoned, even if they were "only" 2D... ... ...!
...and didn't affect the frame rates...!

The 3D cloud types, density, altitude, variation, etc, have to be very carefully selected in FS 2004 to make them appear natural... ...!
I set my clouds up in the flight sim after taking a peek at the sky and the clouds outside of my house, and compare them... 8)...!
To get good frame rates, I generally ignore complex cloud arrangements and select simple Cirrus or Stratus clouds, and set the visibility to 10-20 miles Max.
This gives the fastest frame rates and avoids processing  and showing scenery in the far distance, (which is un-realistic!)... ... 8)...!
Remember that the clouds are one of the biggest frame-rate hoggers in the flight sim...!!
Using this type of Weather selection, I get consistant smooth Frame Rates of 30FPS+.... ...!

For an excellent, simple, free-bee, add-on, weather program, have a peek here...>>>

http://www.avsim.com/

Search for "Weather Maker. Personal Edition".
...and download it...enjoy...!

Cheers all... ...!

Paul The Weather Man.... 8)... ...!