I own G2 and have spent only 45 minutes on Reflex but Reflex is better than G2 for picture and physics. G2 is superior as an interface and for the extra features but picture and physics probably outweigh those features.

I have also spent several hours on G3 and it is superior to Reflex on many levels. Reflex uses photos for the background which looks good but comes with several downsides, you can only fly in front of yourself for example.

Since they are the same price I'd say G3 is the way to go as it has superior physics, looks better than AFP and has more features and is easier to use than any of the others.