I'm sure I'm not alone in finding the D20 character creation process long, drawn out and tedious. Whilst it is well suited for PC's and the most important NPC's, you really need something else should you need the stat's for a minor character your players may need to deal with only once.
Minions Of Mars gives the basic statistics for 22 commonly encountered character types. Each listing has stats for 2nd, 6th and 10th level. To add variety each level has three variants, one at normal ability modifier, one with all mods at +1, and one with all mods at +2. Where appropiate, the different races of Mars are represented.
To round things off, there is a section detailing eight NPC's who could easily be dropped into most campaigns. These characters are interesting and well rounded. There's also a section of four new feats (some of which have featured in earlier AE releases).
Pro's: Cut's down on the GM's workload when creating minor NPC's. The detailed NPC's all have adventure potential.
Con's: Page after page of stat's are visually uninspiring. A lot of the artwork is re-used from the core rulebook.
Overall: Not an essential purchase, but a useful and convenient one.