I bought it and installed it yesterday. I had been using a G2 unit for about the last 3 years. The graphics are indeed way better than the G2, however I don't know how they compare with the G3.5 as I have never used one. A couple of my concerns are with the flight physics with the airplanes. Both are sort of realated--

a. How good are the flight physics when it comes to crashing, a thing I was very good at in G2. With the "hundreds of sensor points for the most realistic reaction to impacts" that is advertised I find it harder to crash damage the planes than it was on the old G2. No it is not from my flying abilities improving to the point I can't crash anymore. As of yet I have not found a way to make the landings more realistic as with the Landing Setting area of the G2. Also when the aircraft leave the runway onto the rough ground the aircraft continue to move as smoothly as if they were still on the runway.

b. You can fly off of water in G4. Water planes float and the land planes sink, everything seems good there. But why is it that I can put the PBY on the runway,wheels up as the plane has no retracts for the wheels or floats like the real model that is being modeled, and make several take-offs and landings with no damage at all? I can see that with the Cub on floats as it also has wheels.

I had to turn down some of the graphics (shadows and reflections and such) as the view on screen was kind of jerky however it is recommended that you have 256 mb video card and I am running a 128 mb card. The largest reduction I used was to reduce the vegitation density to 0% which is ok as when you are flying why would you be looking at the bushes and the grass? The computer I am running is an Intel dual-core at 1.86Ghz and 1 gig of ram with the 128 mb video card and things are running pretty smoothly now.

So far I like the G4 as it graphics are better and with these old eyes I can see the aircraft and be in control more often than not. I would recommend anyone that has a G2 to check their computer to make sure it is above the minimum requirements before they buy this though. If you have a G3 or G3.5 check it out at a hobby shop or friend that has it first to see if it is worth the $200 to upgrade, unless you really NEED to fly off of the water.