The Glorious Model O and Viper Mini are very similar and difficult to compare as they both have pros and cons.
You are eligible for Limited Warranty support for the following periods of time commencing upon the date of retail purchase of your Product Warranty Period.
From within the software you can set up all the RGB until your hearts content.
They are definitely a lot crispier, sharper and more responsive.
As for the side buttons Razer have listened to feedback and made these much easier to press.
The Viper Ultimate and Viper have different side grips which I will talk about in more detail later.