Contrary to what some other internet reviewers try to make you believe, the loader's MG shield is included; it's part B28. Why Dragon marks part B15 (closed loader's hatches) as not for use, but tells you to glue the split hatches in the closed position instead is anybody's guess. Please beware and not make the oft repeated mistake of installing the MG shield in the raised position with the hatches closed. To stay up, the shield needed the front hatch for support. You also have the choice to have the commander's hatch open, closed, or only the small flap opened. A periscope is included.
Dragon let's you install two antenna supports, which technically makes this a Befehlspanzer. I am not sure this is correct for all marking options. A bar is included for the rear of the superstructure, but not the spare tracks that would fit inside.
While the box says the gunner's periscope is a clear part, my kit only has it in grey styrene.

Even the underside of the fenders is detailed.

PE is inlcuded for the engine grilles and one fender support each side. For those that are not into PE, you get styrene parts for some of these as well. Reasonable detail for the gap behind the gun is included, but not for the inside of the vehicle, except for the roof hatches and ventilator.

Two minor errors have been found in the kit so far. The first is with the driver's visor, which is closed. Of course, the driver could close it, but then he would drive blind. The second is with the cupola assembly. Part B18 should be turned 180° with respect to parts B19 and B20 so that the hinge of the hatch does not coincide with a periscope. Note that most of the cupolas of the StuG could be rotated, so you can actually install B18 on the roof as you like, as long as you respect its relative position with respect to the hatch. (There was a period in time when the cupola was fixed due to a lack of ball bearings.)
(Thanks to Robert Kru and Spencer Pollard for drawing my attention to this.)
Note that Joaquín corrected the cupola but left the visor unaltered (see pictures above).

Note that the exact same vehicle can be built from kit 7284 (StuH 42), which also allows other versions to be built.

There are five marking options:
- 2. Pz.Gren.Div. "Das Reich", Russia, 1943. (Actually, I guess they mean the 2 SS Pz.Gren.Div.) Green over dark yellow. Kursk markings.
- Pz.Gren.Div. Grossdeutschland, Eastern Front 1943. Green over dark yellow. I have no clue why Dragon gives you an option to use Balkenkreuze with slanted edges on the white beams.
- 16.Pz.Gren.Div. "RFSS", Italy 1944. I guess that "RFSS" stands for Reichsführer SS, which would make this the 16.SS Pz.Gren.Div. Overall Yellow; rare type of Balkenkreuz.
- 3.Pz.Div. "Totenkopf", Ukraine 1944. Whitewash over dark yellow; 5 silhouettes as "kill marks". If Dragon likes Waffen SS units so much (and I see no particular reason as really many units used this vehicle), why don't they call them by their proper names, here: 3 SS.Pz.Div.
Timothy Lau points out that this vehicle was actually an initieal version of the StuG III Ausf.G, not an early version, which means that the front of the superstructure sides is more vertical than in the kit.
- 1288th SP Gun Rgt. Red Army, Ukraine 1944. White over dark yellow; red slogan. Very original choice.

Picture above from Henk of Holland website, used with permission.