My first bullpup was the Tavor, and the AUG is only an inch or two longer. The AUG seems a bit thinner than the Tavor due to the overall shape of the rifle though. The AUG barrel is more exposed than the Tavor overall, which gives an illusion of being smaller overall.
With the AUG being a bullpup rifle, the action and most of the components are to the rear of the rifle, giving it the illusion of being lighter than a conventional rifle. Though the rifle is over 8 pounds, it actually has the feeling of being only 5 pounds due to the overall balance of the components.
I opted for the 1.5x magnification optic that is built into the receiver. I know alot of people like to choose a railed version of the rifle in order to have whatever optic they want, but I would rather have a sight that can't loose zero easy just by being jarred hard enough. Plus, the charging handle functions are not obstructed by the fixed sight, which is a huge bonus.
Many people find vertical grips to be uncomfortable to use and handle. It is not always a natural method to shoot using a vertical fore-grip, but neither is using the C-clamp method. With the AUG, I found the vertical fore grip to be quite helpful under full auto fire, when I shot one for the first time at Battlefield Vegas. I toyed with a standard forearm hold on the rifle, or at least the idea, and it just did not offer the same control or comfort as the vertical grip.
I noticed right away that the recoil on the AUG, in the old and the new A3 models, has less recoil than the Tavor by a good amount. I would attribute this to the fact that the rifle has a tulip shaped flash hider, and the gas piston is very efficient. Some people like to say that the old style flash hider doesn't do much for the recoil, but if you look at the shape, you can see how the excess gasses will push the flash hider forward, resulting in a forward push against the recoil. The gas system uses a short piston of limited travel that only allows the bolt carrier to be under the influence of the gas pressure for so long before inertia takes over to help finish cycling the rifle.
After about 200 rounds, I have found that the rifle is going to need the help of high powered 5.56 NATO ammo to help the rifle break in properly. The rifle seems to cycle very reliably with steel cased ammo and low powered .223 ammo while in the lower gas pressure setting. I still have 1000 rounds to go through with the rifle to get a good determination of how reliable it is. We shall see how it does.