Please advise on Poland Itinerary

Gdansk, Krakow and Warsaw are the only places. 4N in Gdansk is fine, you can decide once you're there how to divide your time between the city and the side trips. Do allow at least 3 hours for the Solidarity Museum and 2 (maybe more - I missed it) for the WWII museum. Pay attention to which days they are closed . . . I didn't and that's why I missed it. I didn't think there was that much to see/do in Warsaw. 3N may be enough, no more than 4.

Gdansk, Krakow and Warsaw are the only places
Really? I wouldn't like to advise against Torun. It is an absolute beauty, if only for its position on the river.
I find Wroclaw a more interesting city than Poznan and well worth a few nights. It is also a good base for the wonderful so-called Churches of Peace in Swidnica and Jawor, both served by train. (I have a preference for Jawor. In all its simplicity it is more impressive than the more popular one in Swidnica). Try indeed to fit it in.
An easy and worthwhile day trip from Kraków would be Tarnów, only some 1 hr away on fairly regular trains.
I found Malbork somewhat disappointing, but that is personal taste.
In Gdansk don't forget the cathedral in Oliva, easily reached on the suburban train.

You may wish to read my recent trip report, and browse the Poland pages of this newsboard.

https://community.ricksteves.com/travel-forum/trip-reports/four-cities-in-poland-2019

We did two weeks in Poland the summer of 2018. Our itinerary was krakow 6 nights, Wroclaw 2, Gdańsk 3, Warsaw 4. We had a driver from krakow to Wroclaw only because we stopped in Częstochowa. Otherwise we took the train. Definitely upgrade to first class since it is just a few dollars more. The trains were efficient and comfortable. We caught up on some sleep going from Wroclaw to Gdańsk. After our trip I don’t think you can can go wrong with any city you choose. For us it was a toss up between Toruń and Wroclaw. Wroclaw won because of logistics. We found Wroclaw a delight with enough to keep us busy for 3 days. Warsaw was more cosmopolitan and at first we were a little disappointed, but as moved around and got to know the city were enjoyed it more. In fact, we wished we had two more days there to really explore. The Polish uprising museum is a don’t miss as is the ethnographic museum. We definitely want to return to Poland soon to explore the smaller cities we missed.

Some initial notes:

• For your day-trips from Gdansk, Malbork is an excellent choice, although Sopot left a lot to be desired for me. Instead of Sopot, I'd consider exploring the Hel Peninsul, or Gdynia, or best of all - the UNESCO-listed Słowiński National Park.

• If you did want to add another town to explore, instead of Wroclaw or Poznan, I'd recommend 2 nights in the town of Gniezno, which makes more logistical sense. Gniezno is the oldest town in Poland, the birthplace of the Kingdom of Poland, and the first capital, before even Krakow. The best part - hardly any tourists know it exists. You can steal a night from Gdansk and another from Warsaw.

• Also, if you do decide on Gniezno, which you can add after Torun, on the way there, make sure to stop by the Iron Age fortified town of Biskupin, it has a fantastic open air museum of the Iron Age cultures of the area.

• Good on you for choosing to day trip to the Eagles Nest Castle Trail, I did it over this last summer and it was really a great experience, here is my trip report: https://community.ricksteves.com/travel-forum/trip-reports/new-daytrip-from-krakow-eagle-s-nest-castle-trail

I think some text got dropped from Chani's message.

Poland is full of modern, highly-English-accessible museums that can take a lot of time to see, especially if you're interested in 2oth-century history. I'm nuts for that stuff. I spent 20 hours in the WWII museum in Gdansk and 8 hours at the Solidarity Center. POLIN and the Warsaw Rising Museum each took me close to a full day, and they just scratch the surface of what's available in Warsaw, which also has a lot of art. Krakow, though smaller, also has many time-consuming sights.

The above is by way of saying that I certainly don't think you've planned too much time anywhere, and I doubt that you'll have time for Sopot. I spent 5 weeks in Poland last year and didn't have time to see it. I tried to see the church at Oliva but arrived just as a service was about to start, so that didn't work out; research the visiting hours before heading out there if you decide to go.

You don't seem to be rush-around travelers, so I think you'd regret taking time from your planned destinations to fit in Wroclaw or Poznan. Of the two I'd agree Wroclaw has more to see, but be prepared: It has become very touristy. My recommendation is that you accept the need for a second trip to Poland to see some of what you will miss this time.

Critical to book ahead of time: Auschwitz and Schindler Factory, both of whose advance tickets regukarly sell out. And I hit a 20-minute ticket line during one of my visits to the WWII museum in Gdansk; it might be less busy on weekdays--or perhaps it's less busy overall now that it has been open for a few years. But as you will see, Gdansk is very far from being undiscovered.

We took our first (and so far only, sadly), holiday to Poland last year.

It was fantastic and we didn't regret any of our programme. But, you have a shorter timescale than we were lucky to have. So, on our limited experience, here's how I might change it for a shorter visit.

We did Warsaw (4 nights), Gdansk (5), Torun (2), Poznan (4), Wroclaw (only a one night stop-over to break the journey) and Krakow (5). As I wrote above, that suited us fine. But if redoing it with less nights, then I would cut Warsaw to 3. And whilst we loved relaxing in Torun, the sights could be done as a day-trip, so perhaps stay one night. Poznan is delightful, but could be seen in 2 nights. From what little we saw, Wroclaw is also worth 2 or 3 nights. In Krakow we were especially lazy and probably could have "done it" in 3 nights, or perhaps 4 to include Auschwitz.

Mind, that would be too fast travel for us. So, if forced to cut back destinations in order to reduce holiday length, I think we'd reluctantly drop Torun and chose either Poznan or Wroclaw, probably the former.

This is my report, for what its worth:

https://community.ricksteves.com/travel-forum/trip-reports/poland-first-trip