If you have a large network, it's one of the easiest solutions to deploy and manage.
The best part is the single operating system that they have. Regardless of your model, it's the same operating system functioning across the board, which means you don't have to worry about backward compatibilities between your older switches and the new ones that you deploy, which is a big plus when compared to maybe Cisco, HP, or Juniper, where you get into these different operating systems based on the model.
Against that, if you look at the competitors, you always have to worry about the operating system that the older units are running on, and the integration between the old and new, and what are the limitations and stuff like that. All those questions you simply don't have to worry about when you talk about Arista. Therefore, the deployment becomes pretty easy.
The solution is very stable.
Technical support is extremely responsive and helpful.