Medium is one of the two writing services I've been trying out lately, the other one being Quora.
Both services aspire to encourage good writing and insightful contributions, although they don't go about it the same way.
The first thing I'd like to note is that Medium's rich text editor is the best I've seen in a browser so far. I've been involved in the discussions about how to make a rich text editor when we rebuilt XWiki's WYSIWYG editor from scratch, and a lot of difficult decisions had to be made. In the end, we went for a somewhat classic choice, with toolbars and such. Medium offers a clean break from this somewhat dated model.
One of the things I had pushed for at the time but that did not come to fruition were using an inline window to provide editing features, such as for links. Instead, we went for modal dialog boxes. While providing way less features (at least for now), Medium embraces full on this vision of offering the tools you need where you need them.
Highlight some text and you're offered to make it a heading or a link:
This is much better than the clumsy way Gmail now lets you deal with text editing in emails (oh, the back and forth with that dreaded bottom toolbar that keeps hiding all its features).
Hover over the side of the content and you're asked whether you'd like to insert an image:
Simple, clean, efficient and out of the way when you don't need it.
Want to add an article for further reading? The button is available at the bottom of the post:
Also of note is the way the background and application chrome disappear when you're typing, letting you focus on your text. I had only seen this in desktop applications so far.
Other than that, I had a bit of a tough time figuring out how to setup a collection. I initially published in "On startups", a pretty crowded collection, before figuring out that I could also create a collection more focused on the topic at hand: https://medium.com/personal-driver-and-ride-sharing-services
I'm not quite sure how well Medium will fare in terms of promoting distribution of my content compared to Quora. Quora benefits from a large built-in audience and recommendation system ("related questions") which is less developed at Medium. However, Medium currently puts a limit on the number of authors it allows on the system and limits the onboarding of new writers.
While Quora let you see how many readers each question / answer has, Medium provides a simple dashboard to tell you how many views and how many times your articles have been read.
Neither service allow you to use tools such as Google analytics though.
Is Medium for you? Maybe, if you feel that the collection system will allow you to add interesting articles next to other writers. Probably not if you prefer posting on your own home on the web. Whatever your choice, Medium is fun to try for the strength of its rich text editor alone.