Pros
Zentro is a profitable and growing business that makes it exciting and rewarding to work there. In my roughly 5 years working there, it went from a founder-run company with dozens of employees to a regional business with 200 employees. Its growth came from a good mix of organic sales and through acquisition. It's full of smart, creative people who genuinely want the business to deliver good internet at a good price and service level. There's a strong desire to both grow and improve internal operations. The people there are friendly, helpful, and encouraging. There are lots of opportunities to learn new skills, move up in your career, or try something different that come with the high growth, and people are supportive and want you to succeed. You can get a LOT out of working there; I certainly did.
Cons
The high level of growth, particularly through m/a, can bring disorder and uncertainty. Efficiently combining the operations of multiple companies is easier said than done, and it brings out lots of frustrations. I worked on the Process and Innovation team, so my perception of the business is based on my role there (though the people on my team were incredibly talented). Compensation improved a lot since when I started; you can expect market wages.