DX2.0 lipo

the only real advantage i see to running a lipo pack in the DX2.0 instead of 8 AA's, is shaving a bit of weight.

Im looking at getting this Tx pack for my DX2.0, the Rhino 2620 Tx pack. Im unsure though, how much 8 x AA's weigh. Because if they end up weighing the same then i wont worry about fitting a lipo.

I've also seen elsewhere, someone fitting a Turnigy 1600mah 3s 20c to a DX2.0. I checked & the 1600 weighs a little less than the 2620. But would the 1600 still offer more runtime compared to AA's, NiMH or alkaline.

So if any of you have swapped out AA's for lipos in your Tx's, was there a vast difference in weight?