I have Xtreme FSX and it did boost FPS an additional 10. To use the product, you send the support team your FSX.cfg file. They check it, make corrections or additions and send it back. Before using the new one, you back up your present FSX.cfg. Upon using Xtreme FSX for the first time, I checked my FSX setting and I saw all of my sliders maxed out. And the water was set at medium X2. Air traffic was set to 10, road traffic was set to 10, ships and boats set to 6. Airport animations were turned off. Clouds were set to 60 miles. Aircraft shadows were all checked. I tested Xtreme FSX before and after at La Guardia International airport because FPS really take a hit there. My FPS before using Xtreme FSX were at 15, after using Xtreme FSX they were at 20 and depending upon what aircraft I was using FPS would go up to 23. When using Xtreme FSX my FPS are anywhere between 25 to 50 all the time. Also, it appears that my scenery colors are more vibrant. I have tweaked Xtreme FSX a little because it had set my scenery to come into sharp focus at five miles out. I didn't like that so I set the scenery to come into sharp focus at 20 miles out. Doing that lowered my FPS by 2 or 3 but I prefer the scenery to be in focus at 20 miles rather than five. There are a lot of things that one can change in Xtreme FSX if you do not like its default settings. When first running Xtreme FSX it will evaluate your hardware and then adjust FSX to achieve higher FPS. Please see my hardware specifications below to compare with your own. Hope this helps.
Win 7 64bit Pro; Sys Info: Case Cooler Master 690; PSU Antec HCG 900 Watts; Motherbrd ASUS M4N82 Deluxe; CPU Cooler Master Hyper 212+; CPU AMD Phenom II X4 965 Black Ed OC 3.8Ghz; 8GB Patriot DDR2 800 PC2-6400; VidoCard EVGA Superclocked Geforce GTX 470,1.2GB,PCIe X16; Display Drvr 280.26; SoundCard ASUS XonarDX; Logitech Speakers G51, 5.1; Logitech G35 7.1 Headset; Saitek CyborgX Stick and CH Fighter Stick with Pro Pedals; TrackIR-5; Monitor 22" Widescreen SyncMaster Samsung 2233BW