Recs.
Updated
Specs
Pros
Pro Notes can be shared and collaborated on in real-time
MindMeister allows sharing maps with an unlimited number of collaborators so it's possible to take notes and brainstorm together. Mind maps can be shared by inviting people either directly via email or by sending them a link to the map. Even people without a MindMeister account can access the maps and even edit them.
Pro Clear overview without losing any details
The mind mapping format provides with a clear overview of connections, hierarchies and relationships of notes. At the same time, it's possible to add more detailed notes, links, pictures and even whole files to the keywords, so that no important information gets lost.
Pro Adding a Table or Matrix
Xmind is one of the few mind maps that allows you to add a table or matrix to your mind map. Very useful when you have content that works better in a table.
Cons
Con No good offline mode
You can only work completely offline when using an iOS or Android device. For your browser there's only a clumsy 'offline mode' available. If you didn't hit the switch before you have the need for working offline (for instance: in a meeting, at a customer's location, in a plane, etc.) than your out of luck... no tool for note taking. Especially with all those HTML5-capable browsers and the Chrome App store (including Desktop apps), this limits the usage of this commercial product.
Con Expensive compared to the competition
A basic monthly subscription ($92 USD) gives you no more than XMind FREE except PDF exporting. XMind paid with PDF export is $79. $20 less for lifetime use of an app with more features as of writing.
Con MindMeister has very poor Evernote integration
Evernote is the number one 'store-everything-archive' when it comes to unstructured data or information. MindMeister markets there Evernote integration as a very cool feature. But this integration is very basic and buggy: only the last 50 (?) notes from Evernote's default notebook are shown in the list, and it takes about 30 seconds to one full minute to generate that list. After that it takes about the same amount of time to add a copy of the selected note as an attachment to a topic. MindMeister support is well aware of this poor implementation, but doesn't put any effort in fixing it.