The week before last I ordered a pair of Triton 2's and a SuperSat 60c. They are supposed to arrive this Monday. Now my focus is on the rear surround speakers. I'm bouncing back and forth between the Aon 3's and the SuperSat 3's. What will I gain going with the Aon's? Since I'm using them as rears, will I notice a big difference in sound between the two? I have not been able to do a comparison between the two as rears. They will be wall mounted approximately 4.5 ft behind the listening position and approximately 8 ft high.

MoBrien,
That sounds like an incredible system you are putting together!!!
I am sure the Moderator will give you better advice, but my two cents worth is to always go for the best you can. Therefore, the Aon 3s.
BUT, having said that, it sounds like you are going to use this system primarily for movies, is that right? IF so, then there is probably no real advantage to the Aons over the SS3s and the SS3s will look better mounted up high like that.
I love surround sound music, in particular, Blu-ray concerts in DTS-HD-MA. For this and some concert 5.1 SACDs you can get some very good content from the rear channels. In this case I think the Aon 3s would be better, but mounted much lower, nearer the ear level if possible.
In either case I am sure you are onto a winner.
Enjoy!!!!

The Aon is a full-range bookshelf speaker, not a satellite like the SuperSat. With an appropriate crossover frequency there will be little if any difference in a surround application. However, some people do prefer a more full range surround speaker (especially for larger rooms where the surrounds are further away from the Triton subs), in which case the Aon would be preferred - IF you can tolerate its larger size in your surround location.