Im with Tom on this one.
Where I may not shoot with AEGs too often, I do however use heavyweight BBs for my sniper platform. These weights vary to keep the shots accurate. And of course depends on the conditions. However I try to keep the weight consistent since I hate adjusting my hop up over and over again.
Once you start shooting over 500 fps you will want to use heavier weight BBs to keep the accuracy and gain some range...sacrificing fps for a straight shot is fine with me. Different brands shoot differently. When I was shooting under 500 MAdbulls were working great, but now I use Goldenball or the SGM .29s (Best on the market)
But of course now I have to readjust everything once I find a suitable Bio BB to put through.