Avantages
As an employee, you get approximately 90% discounted software. You have so many resources to learn the products at your fingertips, if you have the will to learn, there's a way. Your ideas will get heard - There is a saying at Adobe that "Good ideas come from everywhere in the company" and you see it a lot. People with good ideas will be heard and recognized when the idea comes to fruition. Adobe also makes sure it's employees are comfortable and happy there. A good work/home life balance is encouraged. There isn't a lot of turnover at Adobe either. If you are hired on, you'll likely be there a long time if you want to (and most people do want to).
Inconvénients
Because it's a large company, with offices all over the world, thousands of employees and may cultures working together, it can sometimes take a long time to make changes. This could be a good thing, since it usually means there are a lot of people involved for checks and balances, but if a change needs to happen soon, the size of the company can slow it down. Another aspect of Adobe that is usually a positive but can sometimes be viewed negatively is that most people have their own office. This is great if you need peace and quite to work effectively but in some cases, it's easy to become isolated from others in the company if you never leave your office.