Strengths: Superb grease and grime cutting strength. Good penetration. Wonderful smell. Easy on your gear and hands. Safe to use on finishes, decals, and fabrics(like chain stay protectors). Highly visible. No residue. Easy application. No mess.
Weaknesses: The foaming goes away fairly rapidly (over the course of a minute or two), but it lasts just long to get the job done. That just means that you clean your chain before or after you wash the frame, rather than spraying all of your cleaners on at once.
ProGold's foaming citrus degreaser is one of my favorite cleaning products for regular use. It's pleasant to use, works like a champ, and is a valued tool in keeping all my bikes in top shape. I even like that they include the small red pipe to apply it on a pin point, exactly where it needs to go. That really helps to get it in all the nooks and crannies of a derailleur. Bottom line is that if this isn't in your cleaning pail, it should be.