If you were arriving in Vienna on early afternoon Saturday and leaving Wednesday morning; would you take a day trip to Salzburg, Melk Abbey, Sopron, somewhere else or just stay in Vienna?
I’d go to Melk and the Wachau.
As a note, you should have posted this question in the Austria forum.
Have you been to Vienna before? If not, it is a city worth staying in and seeing all the sites. It is my top favorite cities in Europe!
You can spend a day touring the Schonbrunn Palace, spend time at the Sisi Musuem, and seeing the Hofburg Imperial apartments, go to St Peter's Chruch, go to Karlskirche, there is the Albertina Museum, and my favorite museum Kinsthistorishes. I loved the horse show at the Spanish riding School. There are concerts every night of the week. I enjoyed the Leopold musuem, the Sucession building, and I spent the day at the Belevedere Palace. I also attended an opera in Vienna. I have been there twice and there are lots of lovely cafes to have lunch and desert. Big on cafe culture in Vienna. I also enjoyed the Imperial Furniture collection.
Have you looked at the free RS videos and other videos on YouTube and read the RS guide books on Vienna. Lots to see and do and walking around the city.
Hope this helps.
There is a so much to see and do in Vienna, I wouldn’t even consider going elsewhere. Our first visit was 5 days long. We liked it so much that we returned the next year for a week. In all that time, the only place we revisited was the Kunsthistorisches Museum, which is too big to take in at one hit, anyway. There are still a few places tabbed in my guidebook that we didn’t get to.
Everybody is right. You don't have enough time for Vienna, but never miss Melk.