I do. I use the Osmocote when potting up initially and a fresh application every spring for all permanent container plantings. The Dyna Gro I use only hit or miss (read: infrequently) during the growing season, more as a method of using up the excess from other applications than an intended fertilization. The Osmocote takes care of the bulk of the nutrient needs...the Dyna Gro is just a supplement to provide what might be missing (not much).

Sure. I add a slow release fertilizer when potting, as a backup, and use a liquid fertilizer on a regular basis. It's a great combination, imo.