Melk Abbey or Salzburg?

I really enjoyed my trip to Melk Abbey and the cruise on the Danube to Krems, but that was in July and the weather was spectacular. I'm sure if you have a nice autumn day in October it would also be wonderful. Is the tour to Salzburg a bus tour? Unless it's a really long tour day (11-12 hrs) you'll only get about 3 hrs in Salzburg and 6 hrs on the bus (3 hrs each way), probably not the way I'd like to spend a day trip. But, that being said, I did love Salzburg and I'm sure you'd enjoyed your time there. Only you can decide if the travel time is worth it.

I did both as day trips when in Vienna in 2014; looking back, if I could have chosen only one it would have been Salzburg. The Melk/Danube cruise is appealing due to the proximity to Vienna and while Melk is certainly a beautiful abbey and charming little town, and the views along the Danube are gorgeous, overall I felt Salzburg had much more to offer.

I took an early train from Vienna and 3 hours later arrived in Salzburg, around 9:30 am. At the train station I bought a HoHo ticket and that gave me a great overview of the main sites in the town as well as outlying areas. It was a cold, drizzly Sunday in August so for me that was the best way to see a bit of everything and then linger at what I found interesting--I exited the bus at Mirabell gardens, then spent a couple of hours touring Hellbrunn palace and fabulous gardens, then back to the old town where I spent the rest of my day exploring the town, touring Mozart's Gebursthaus, had a late lunch at TriAngel and I was happy to discover a handcraft fair going on along the river. Back to the train station to catch the 5 pm to Vienna.

We’ve recently been to a holiday in Austria with my 2 sisters and some friends. We explored Vienna, Salzburg, Melk Abbey, Innsbruck. I advise you to choose for Salzburg as it is more picturesque then the Melk Abbey. First of all, Salzburg is the birth place of Mozart and his birth house has been turned into a magnificent museum. Also, the city centre of Salzburg is part of the World Heritage of UNESCO due to its high quality marvelous buildings dating to the late Middle Ages to the 20th century. You have so many tourist sites in Salzburg – the cozy city centre with excellent Austrian shops, the Mirabell Gardens and the Mirabell Palace where classical concerts take place, the Fortress Hohensalzburg. The Salzburg River adds up to the romantic atmosphere of the city.

Why take a tour? Both of these trips are very easy to do yourself. Between the two, in October, I'd pick Salzburg even though it is about an hour more travel time each way. October in the area of Melk Abbey is not the best time to visit, in my opinion, unless it is one of those warm, bright fall days.

Hands down to the combo ticket for Melk and the cruise.
We just were in Vienna and it was a wonderful, easy-to-do trip. There's lots of posts on many forums on this trip to help us. We had no problem getting to Melk, touring the Abbey and gardens, cruising down the Danube and visiting Durnstein. From there it is was a short bus ride to Krems train station and back to Vienna.
Some conclusions from our day trip:
1. We took the tour (in English) at the Abbey. You can visit on your own but I don't think I could understand or appreciate what I saw without a guide. We got background information and little interesting stories that really made the history of the Abbey alive. In my opinion, the guided tour is a must and it's only an hour.
2. Don't skip the gardens. There are the formal gardens and then a series of larger,natural gardens that are absolutely delightful. You can go around them in 30-45 minutes. It's worth taking an earlier train to go around the gardens before the tour.
3. We discovered the hard way that you have to get to the boat early if you want to get a seat (we took the 13:45 boat)! We took our time wandering around Melk, having something to eat and when we got on the boat about 20 minutes before it left we couldn't find a table to ourselves. Many "prime tables" were reserved (I had no idea how to reserve ahead of time.) Luckily I saw a family who had been on the Abbey tour sitting at two tables and I asked if we could join them. Otherwise, my husband and I wouldn't have been able to sit together.
Several posters wrote not to bother eating in town because there's food on the boat and I want to second that. The boat has a real restaurant (light food and main courses) and we should have just come early and eaten there (and found a table to ourselves!).
4. We got off at Durnstein like everyone recommended, walked around for about an hour, caught the 16:40 bus to Krems train station and got the train back to Vienna. Easy peasy!