Pros
Technology - Extreme really does have a solid wired and wireless offering that competes well in the market. The pre-sales engineering folks are great to work with. If you hit your number you will make good money. I did.
Cons
Leadership - especially on the sales side. It's either non-existent, stoic and calculating, or passive-aggressive. (This was my experience.) Extreme is also a bit on the low-side when it comes to total compensation. Based on my research, Cisco, Juniper, Arista and HPE offer more in terms of total OTE. Even though Extreme does have decent technology, no one seems to know it. They are a small fraction of the entire networking market. I have even spoken to customers who have never heard of them. (And they've been in business since the 1990s.) Market awareness is sorely lacking. Turnover is a huge problem. I was on a team of 16 people, and at one year and six months, I was the 3rd-longest tenured person on the team. Not good. Thus, territories and quotas change more than the weather.