Ranked in these QuestionsQuestion Ranking
Pro Great fast documentation lookup
Has a handy sublime plugin. Press CTRL-H and it jumps straight to the docs for that object.
Pro Integrates well with a good selection of apps
They provide very useful integration with apps that are very fitting with using Dash's features. Once integrated, you can really get the feel for being a must have part of the app its integrating with.
Pro Great utility app to use for snippets
Snippet apps come in various forms, such as basic snippet (text) containers and added features with text / keyboard utilities to name a couple. This app not only includes this feature, but takes it a bit further than most by adding unique ways to further customize this practice to your own preference.
Pro Easy to create new docsets in case there isn't one that exits already
Gives plenty of guides and information on how to generate a docset.
Con Forced wait time to view docs
If you use the free version you are very often forced to wait 10 seconds to view something you've chosen to look at. If you change apps or lose focus of Dash, it'll start that 10 second timer over again. A real crappy thing to do to your users in order to get them to buy it. Forcing you to waste your time.