Vantaggi
There are people who genuinely care about their employees and seek to actively develop them. I started as an operations associate (entry level engineer) and had one manager in particular who was extremely helpful. Pay was a little above average for similar positions, and growth opportunities were definitely available. To an extent, the harder you worked, the more you got out (as long as you made sure upper management was aware of your involvement). The company as a whole though is a different story.
Svantaggi
For every great manager, there are two not so great managers. The manager I had before I quit was one of the most difficult to work with. Constant micromanaging, consistently saying one thing and doing another, spending company money on unnecessary items and overly expense meals, and almost exclusively took credit for employee contributions unless he couldn't. Three years of employee reviews going over this led to nothing being done. I was lucky enough to only have him as a manager for about 9 months. I was the 6th person to leave his department in a year, the second in the "supervisor" role. There was a systemic problem completely ignored. On a larger scale, the company regurgitated rhetoric about administration regulation causing their struggles while ignoring the internal choices from top level management which caused a massive hemorrhage of funds. The results were almost used blindly, and likely caused more damage in the end.