A good episode, though part two is a bit of a letdown. Never thought Shelby came across as "wonderful" but, rather, obnoxious: scheming, obsessed, tactical, arrogant. More like John McCain nowadays than James T. Kirk. She makes for a good foil for Riker, and the actress playing her looks like the straight-for-the-jugular type. Her "take no prisoners"/"end justifies the means" approach would make her scary to work with.
I've got to go with Basil here. Shelby is also reckless and has a cavalier attitude when it comes to risking the lives of others. In the real military of today and even more so in the future, she would never have achieved the rank of Commander with such poor leadership skills.