Best used as a stepping stone, there are opportunities for advancement, at the cost of stressThe good thingsThey often advertised opportunities for career progress, including things like secondments for leadership or administration positions (more on that later). They generally keep you with your training team so your team feels far more like a group of friends working together than just random coworkers.
The challengesThey don't treat all employees equally, if you don't care, they are so desperate for hires that they won't fire you, but if you are a good worker and you have an off day they will immediately question you and hound you to do better. Their promotion system is suspect, I was 'lucky' enough to be chosen for a secondment position into the HR team. On any given day, my roster could be updated to work the HR role, what this also meant was that I could be told to leave HR and work phones that day, what this meant, was not knowing my roster in advance and constant anxiety over what I was going to do that day. In addition to this, because I was seconded, annual/sick leave was paid at minimum wage, not the increased wage for working in HR, regardless of if I was rostered on to HR that day. This was the same for all leadership (team leaders, HR, training). In the entire duration I was there, no one in HR filled the secondment permanently, even the HR leader was seconded.