I recently purchased the Walmart exclusive Iron Man Mark VI and War Machine exclusive 6" figures.

They were $12.92 CAD each, which is a pretty darn good deal when I consider that the 3.75" figures are normally $9.99 here.
The sculpting is great and the paint apps are great except for the upper thighs of Iron Man, which look like someone just used a red marker to colour over the gold paint.
The points of articulation are as follows:
- Hands use swivel/hinge combo joints.
- The ankles use ball joints.
- Double hinged knees and elbows.
- The thighs use swivel joints.
- The hips use ball hinge joints.
- No waist joint but...
- Ball joint within the torso(ribcage) to allow pivoting.
- Shoulders use swivel/hinge combo joints.
- Shoulder armour pieces are hinged at the torso armour.
- Ball joint used at the base of the head and hinged joint at the neck, which allows hinged and swivel movement.
The lack of a waist joint, limited ankle articulation, and the way that the shoulder armour hinges to the torso armour are areas of weakness for the articulation but the other points of articulation somewhat makes up for the shortcomings. The neck articulation is surprisingly good as the figures can look up about 135 degrees and down at the ground.
War Machine comes with a gatling gun attached to the figure. The gun has a few joints to allow a full range of movement. An ammow belt made out of soft PVC or rubber is included for the gatling gun. A missile pod is also included to peg into the figure's right upper chest armour. If you don't want to display the figure with the missile pod, Hasbro has included a piece of armour to cover up the peg hole.
Iron Man comes with a spring loaded missile launcher, which appears identical, except for scale, to the 3.75" Iron Man Mark VI figure.
Both figures come with 3 pairs of hands each: A pair of fists, a pair of somewhat open/grip hands, and a pair of open/repulsor blast hands.
If you only want one of the figures or can only buy one, consider the following:
If you like more intimidating looking powered armour, War Machine is the way to go. In addition to the great sculpting and paint apps, there are some great details like what appear to be military vehicle markings all over the armour, yellow and black caution stripes on the forearm cannons, and red triangles(I'm not sure what they're supposed to mean, if they mean anything at all.) on the helmet.

The Iron Man Mark VI figure is for those who like more streamlined mechanical designs. The bright colours, curved forms, and no obvious armaments, the Mark VI is more like a sports car while War Machine is like a tank. If you like sleek and sexy designs or are a fan of powered armour designs like those of the Hardsuits from Bubblegum Crisis, the Mark VI is the figure for you.

At a $13 CAD price tag, these action figures are worth every penny.