While no magic bullet, when incorporated into a Paragraph Style definition, this feature is useful for preventing unequal line lengths in heading and subheadings. Of course, it doesn’t know how to break for sense, so you still have to manually check your headlines and insert line breaks where necessary to move words down to the next line, but Balance Ragged Lines will definitely reduce your workload.
#7 OpenType Support
The latest and greatest in font technology, OpenType, is cross-platform and offers vastly expanded character sets that can include different numbering styles, fractions, foreign characters, and ornaments—to name but a few. Recalling the time-consuming hassle of working with expert sets or trying to remember the arcane naming conventions of Multiple Master fonts, I sometimes feel like saying a prayer of thanks every time I incorporate such typographic refinements as proportional oldstyle numerals and discretionary ligatures into a Paragraph Style definition. (And while not exactly a feature, it certainly is a huge asset that InDesign comes packaged with several OpenType families.)