2 respondents felt that no staff time had been relieved from the issue desk, but the other 4 felt that issue desk time had been released for other tasks. Some sites have re-barcoded their stock, which is costly and time consuming. Others have chosen not to, but it is important that the barcodes should be located in a consistent position. Publicity is crucial to ensure that the system is used.
Problems seem to be in the hardware and reliability of scanners.
One drawback is that the machines will not issue if a ticket has any kind of message on it. The reader is not informed why a transaction is unsuccessful and this can generate confrontational situations. Thank you again to everyone who took the time to reply.