My family and I (wife and two kids, ages 11 and 13) had a one night overnight in Melk during a road trip through Austria. We wish we would have stayed two nights, it was such a charming town. As we had four people, we booked the suite and were pleasantly surprised to see there was a sauna in the bathroom and a huge shower. This was a highlight, we enjoyed the sauna morning and night. There is a shared balcony at the hotel overlooking the town square which is really charming and fun for people watching. My wife and I shared a bottle of sparkling wine from the balcony and relaxed in the afternoon. The service was friendly and there was a parking lot behind the hotel which was very convenient.
The town of Melk was great; lots of charming cobblestone streets, little cafes, interesting restaurants, ice cream shops, etc.. You can also walk across a bridge for a nice nature walk through the woods to the Danube River. The monastery is a must see; it towers over the town and is beautiful. It is an incredible building with great history.
I highly recommend this hotel for your stay in Melk