Not much. At the start of their employment, employees are filled with illusions about defending employees, but when reality hits them (authoritarian and incompetent management, annual membership recruitment targets of 100 per year, no support for training in labor and social insurance law, pressure from members and during conflicts) this leads to disillusionment and burn-out.
Pseudo-comradeship doesn't exist, there are constant backstabbings, and wages are low compared to other unions (SEV, SSP, Syndicom).
Endless working hours, evenings and weekends. Management always plays on the vagueness of militancy to avoid counting working hours, but it's always a constraint and an obligation for managers.
The worst-shod cobbler of any employer I've ever met, and one to be avoided as quickly as possible.