Engine Sound Creations has released their contrails addon for FS9 and FSX at SimMarket. They proudly presents, according to themselves, the most realistic contrail effect for FS2004 and FSX. This new enhanced contrail effect will bring your flying experience to a new level.
I still fly my FSX with Contrails Pro by Flightsim Tools and was quite happy with it until now. Looking at these screenshots I believe it's time to change to the ESC addon. In my opinion it all looks just a little better. Sorry Flightsim Tools, you just got defeated.
More info and features here at SimMarket.