Overall they have a nice POS interface and it is pretty stable. Their pricing is also pretty good for the base system.
The bets thing about Revel apart from the easy to use interface is the support team - I have been super impressed with the help I have received in setting up my new POS Revel system.
Was a great price and it integrated seamlessly with my QuickBooks Online software.
Then they're arrogant as hell about it. Don't even get me started on how painful, slow and counter-intuitive the backend is.
Terminals went out of sync with each other and caused major problems with ordering and reports, affected customer service. Every time Apple does an update the system does not work (2-3 times a year).
Terrible Company and even worst with the way they conduct their selves. Their sales reps are liars and only care about making the initial sale.