The biggest issue for me comes from working on the hotel side. You're treated as a red-headed step child by the hotel. You're expected to follow all of ITA's rules and the hotel's rules. You'll be treated like a member of the family by the hotel, right up until they either desperately need something for free or need a scapegoat. Oh, and if they don't think you're a good fit for the hotel anymore, or if the hotel GM just decides he just doesn't like you, then you're out.
Be prepared to work more than you expected to during the busy seasons. Events can change or even just pop up at the last moment.
Career advancement: If you work at a field site and you don't desire to move to Cincinnati, then your only chances at advancement comes from one of the regional managers leaving the company.
Incentives to excel: There is only one. Beat your revenue goals for the year and get an extra 1% wage increase at your yearly review. Other than that, there is nothing. Come in at #1 for customer service out of 350 hotels in your brand and you might get an email saying good job. Steal a $15,000 event from a competitor at the last moment and you might get an email. Consistently meet your labor to revenue goals and your only reward is being allowed to ignore the angry emails sent out each week.
You'll almost never see a tip. Even if you're absolutely the only thing the client enjoyed, their tips are handled through the hotel's bill. Which goes to banquet employees.
The only true reason to excel at ITA is because you take pride in what you do.