The Glycerin is Brooks' soft trainer, and the 22 is the one that brought in DNA Tuned: a nitrogen-infused midsole with large foam cells under the heel for soft landings and smaller ones under the forefoot to firm up the toe-off. It keeps the 10 mm drop of the Ghost but sits noticeably plusher underfoot.
It suits you if most of your mileage is easy and you want the shoe to absorb rather than answer. It is a comfortable long-run shoe on road, and the obvious move if the Ghost has always felt a touch firm to you.
It is not a workout shoe. There is no plate and no snap, so hard efforts in it flatter nobody, and it is a lot of shoe to carry around a 5K.