I arrived at the desk to buy a ticket about two minutes before a scheduled departure of the Flyer. I was glad to make it since the bus only runs every half hour, despite being at a very busy airport. The man at the counter apparently did not like that I wanted to use a credit card, and suggested that I might miss the bus while the transaction processed. I was out of town, so hardly wanted to use cash. I went with credit. The same man ended up being the man who checks tickets before you leave. Obviously I wasn't going to miss the bus.
The bus itself was clean and the ride progressed quickly once we got going. The drivers are very friendly.