Originally Posted by
jamar
I've always used the S7 to go into town from Vienna. I only ever used the CAT in the other direction when I needed the early check-in and bag drop service.
Exactly, the only reasons to take the CAT were if you wanted the baggage service, or if you are about to miss your flight.
But there was only 50% chance of CAT being the next train, because the S7 and CAT run at 30 minute intervals, roughly every 15 minutes in combination. The journey takes 15-20 minutes. If you have just missed a CAT service, the next S7 may be at the airport almost before the next CAT departs the city (and vice versa).
On the way to the city unless you must go to Mitte, there are many more options with a standard Vienna ticket.