An absurd amount of regulation. Feels almost "Big Brother"-ish. You must account for/track how you spend (quite literally) every minute of the day. Client work load varies every day, making it virtually impossible to predict how much actual work you will have to do, yet you are restricted in how much "overhead" work you can have in a day. Flexibility is touted, yet your schedule and response time standards make that non-existent. There is a large dichotomy between the rules/regulations/expectations for ZAs, and the "regular" employees (who all get the luxury of having their own ZA). Pay is pretty terrible for a full-time position with benefits. Some people work 2 jobs to make ends meet.
Instead of listening to concerns, more rules and procedures are handed down from people who have never even been a ZA, or supported actual clients of their own. Support will often not back up the ZA when clients have complaints. Clients can really do whatever they wish and Support will, most of the time, back them up, or give in to their whims, even if the client was indeed wrong. The ZA then has to take the blame and salvage the relationship, even though they were made to look foolish and unprofessional, out of no fault of their own.
Management has "incentivized" their staff by providing bonus opportunities. The promise of a bonus isn't worth the day-to-day pressure, stress, and hassle of remaining an employee.