Why Kentico - Developers
The first audience I want to speak to is Developers. Someone has to build the website, and this person we will label the "Developer." In some CMS Platforms, a Developer needs to know certain coding languages extensively, be it MVC, PHP, or the likes.
You don't need to be a Developer, to be a basic Developer
The first point that makes Kentico awesome is you don't need a computer science degree to build in Kentico. In fact, Kentico provides the tools to build your entire site without touching code. Yes that's right, you can define your html templates, add functionality, create all your dynamic stuff, without knowing any .Net code at all. I've built entire sites where i've never once went into the back end code. This is thanks to Kentico's Awesome "Portal Method" which has the philosophy "You should be able to do manage your site through the web portal."
If you are a Developer, being a Kentico Developer is easy!
Needless to say, customers will usually want some sort of custom requirement, or special logic (like importing content from a seperate system). Other CMS system's I've worked in, developing was HARD. The Documentation was non-existant, the API was limited, and there were no good examples to go off of.
Kentico is different in many different areas.
Kentico has an Awesome API
Kentico's API is without a doubt the most expansive i've ever worked with. They have functions and methods for everything, and very well organized. There's not an aspect of Kentico that you can't control through the API, which means there's nothing you can't do.
Kentico has Documentation
Kentico has documentation. But not just any documentation, it has a HUGE documentation portal that tells you how to do everything, from basic stuff to the most complex items. It also provides API example code so you can know exactly how to utilize the API.
Kentico has an "Open" Philosophy
I've worked in some CMS systems where all their interfaces (like adding users, editing rolls) were locked down, hidden in compiled drivers. You couldn't figure out how they did any of it. But Kentico has all it's user interfaces open and available, so if you want to replicate something, you can actually see how they did it, so you can modify that.
Kentico has Standards
Kentico has standard coding practices, from how things are organized, to how to create custom modules, web parts, how to keep your site and code secure and fast. They outline all of this in their Best Practices for Customization and Securing your Website documents.
Kentico has a Community and Support
Kentico has your back. First there is the DevNet, where you can ask questions and knowledgable Kentico enthusiasts (like myself) can help you. If that doesn't get you anywhere, Kentico's support team is without a doubt the friendliest and most helpful support team i've worked with. I've utilized them on many occasions, and they have always helped me out.