No doubt, the functionality is great. Odin offers a lot to make nice designs for your Unity Editor, BUT... - be careful about the non-standard EULA, it is not a "buy and forget" thing. I am a total opponent of assets, which ask for non-industry-standard/special treatment, especially when this is introduced AFTER buying the asset. It comes with additional management/administrative work, as you must keep track of such assets and their special conditions. E.g.: Additional licenses may be required based on the project/team composition, your revenue from last 12 months, ... - there are (free) alternatives out there, which offer a large set of Odin's functionality. Sure, Odin offers more, STILL... ... if you consider price/license/performance compared to the competition, I can't recommend Odin anymore. Alternatives cover a sufficient feature amount as of today.

Since the moment I tried Odin, it has been an absolutely essential part of my coding workflow. If you are solo: You can make the inspector do almost anything you can think of, to the point of dang near making minigames in the inspector itself. It's that powerful. If you're part of a Team: You can make inspectors that are absolutely BULLETPROOF, with handy tooltips, easy settings buttons, re-orderable lists and arrays, Hiding unneeded references/variables based on bools, and much MUCH more, so your artists and level designers can unleash their creativity without you getting upset at them because they forgot to put in a certain reference or enabled the wrong variable :) It's worth every cent, and that's before getting into the new visual designer in 4.0 that made it even EASIER to make those custom inspectors. 10/5 would buy again.

it changed all my unity capabilities

Litterally this is borderline the unity editor customization equivalent of the step between Dos and Windows for operating systems.

Odin is one of the best investiments you can make on your project.

Odin has been so easy to use and people on the Discord are very helpful. With the latest release the Visual Designer tool makes things sooo much easier.

新功能很好用，不用等代码编译马上就能看到效果

I really regret buying it. I bought you to save time, not to read the copyright notice

Unity's greatest strength is the customizable UI, but actually writing custom inspectors from scratch is a major challenge and a considerable investment. The Odin suite lets you build designer-friendly tools in a quick, easy and – most importantly – maintainable manner. You can learn it in an afternoon and is useful at pretty much every stage in a project. While you're prototyping and figuring things out, you can easily build yourself debug tools that save you from constantly starting and stopping the game to perform tests, simplifies data structures by serializing collections like Dictionaries, taking a lot of friction out of the process. While in production, you can respond extremely quickly and efficiently to requests from art and design, or even just train them to make their own tools. It's that simple, it's that powerful. Odin is the first (and usually only) asset I import when starting a new project, and it's literally the only one I recommend without any qualifications to all other developers. Save yourself a bunch of trouble, make your team happier and more productive, enjoy Unity the way it was intended to be used without jumping through all the burning hoops presented by the editor scripting API.

if you want to create good looking inspector stuff, this is the easiest way