The aug might be heavier but all the weight is at the rear If you get a basic non ris short variant. The gearbox and battery both sit behind the pistol grip and this allows you to let the gun pivot into the shoulder as you use it.
It makes them very easy to carry and shoot. The mags are also all plastic, and there is a good selection of sizes available. The 110-170 round mid caps are superb as they don't rattle and give enough shots that you do not need to constantly swap mags.
Internally the aug uses a V3 gearbox with some slight modification to the trigger setup. So pretty much all parts are easy to get. The only thing you have to watch is the length of the airseal nozzle as there is some deviance in manufacturer lengths.
Out of the box most augs need very little doing, but most do benefit from steel bushings, re-shimming and a metal spring guide if it's a gun you plan to use all the time.
The biggest disadvantages of the AUG are,
It's a noisy gun for the shooter, Your ear sits over the gearbox most of the time. POM piston and cylinder heads go a long way to helping with this, but arn't a necessary upgrade.
They can have some trigger contact issues with the single shot contacts, but parts can be home made for them.
The inner wall/gearbox plate is screws into plastic, and you can very easily strip the threads and have to go up a screw size.
The battery space is limited, but a well selected 7.4v 2200mAh lipo will fit.
The dual stage trigger takes a little getting used to, it can be modified so you get single shot only, and single/full auto. All you have to do is file some plastic from the selector pin. Some of the newer models already have this mod done out of the box.
The best thing you can do is go down to a shop and just pick up and handle as many guns as possible. Then take the model numbers of the variants you like and go searching online for reviews.