I just returned from a weekend in Warsaw (which includes a massive clock tower - see above). It was an absolutely fascinating experience. Aside from a few days in Berlin (including East Berlin) several years ago, it's the first time I've spent in any formerly communist country. (I'm also not counting Shanghai here, which is a wholly different situation.)
The owner of the vacation apartment we rented (he insisted on being paid in cash upfront; the apartment was clean and had a functional kitchenette, but was otherwise relatively bare and in a building otherwise in relatively poor disrepair), who spent a year living in Sweden, commented to me that he liked Warsaw better, because Sweden was too clean and orderly and Warsaw was grittier. I agree with his descriptions, but disagree with his preference.
As some examples, on our first day when walking into the subway, we walked by a women with a black eye, limping as if someone had just beaten her up. (I'd hope that she was going home after receiving the appropriate care and concern from the authorities and heath officials...). On a more mundane note, nothing was particularly clean or new, and some parts of the central station looked like the shop that was previously there had been just ripped out of the wall.
That said, the public transit system was actually excellent, with buses, subways, and trolley. Getting to and from the airport was very easy (take the 175 or 188 bus and then switch to the subway or trolley) and a great planning site. You can also get a day pass for 9 zl (~$3) good for 24 hours once validated (perfect for after Shabbat and Sunday), though no one ever checked our tickets on a bus or trolley.
Customer service, on the other hand, was not so great. For example, after checking out we put our bags in a locker for the day before heading to the airport. Upon returning to them, we had a very hard time getting the machine to accept a 1 zl coin and unlock our luggage. If we hadn't gotten it to work (through some combination of backspin on the coin and sheer luck), I'm not sure what we would have done. The one worker at the information station upstairs spoke no English, and there was no one else around. Our best bet may have been to break into the locker and hope no one noticed.
One of our goals in Warsaw was to see evidence of the Warsaw Ghetto and Jewish uprising there in 1943 that every Jewish child learns about in Hebrew school. We able to find a section of the ghetto's original wall (see above, between Seina and Zlota Streets, enter at 55 Seinna) as well as numerous monuments in Hebrew, Polish, and English.
We also thought that we would go to the Uprising Museum, which was supposed to be excellent and have lots of English. When we got there, the line was literally "out the door and around the corner." One of the guards said that it (August 1) was the anniversary of the beginning of the uprising, and so is a very popular day to come to the museum. (There was a large ceremony going on outside.)
This seemed odd to me, since I had learned that Yom Hashoah (Holocaust Remembrance Day) was celebrated in the spring because of the Warsaw Ghetto Uprising. So how could this uprising have begun in August, long after the Ghetto Uprising had been crushed?
It seems that this museum was actually for the Warsaw Uprising, which took place in 1944. (Wikipedia shows you both links.) This was after the vast majority of Polish Jews had been murdered, and represented a much larger, coordinated, Polish military effort against the occupying Nazi army. It seems that, in anticipation of the advancing Soviet army from the east, Polish leaders tried to defeat the Nazis first, in an attempt to reclaim their independence, in part in the face of future Soviet hegemony.
Stalin, however, after encouraging the Poles to revolt, double crossed them and halted his army, allowing the battered Nazis to defeat the uprising, diminishing hopes of true Polish independence. To make matters worse, Stalin later persecuted those who had organized the uprising, likely to remove potential threats to his own totalitarian regime. In fact, this museum is only a few years old, as it would have been impossible to build it in Communist Poland.
As for the Jewish community, we went to Friday night services and Shabbat dinner. It's an Orthodox shul, with all of the gender inequality that comes with that. Furthermore, the vast majority of the people there seemed to be heloni (secular) Israeli tourists, and so I found the overall davening experience somewhat lacking, though, it reminded me how very much missing davening with a minyan on Friday nights this past summer. Shabbat dinner was much smaller and lovely, and is worth attending if you're looking for somewhere to spend Shabbat in that region.
A few interesting notes about the synagogue: Becoming a member of the community seems very arduous. I've never heard of an American shul doing such a litmus test on potential members. Maybe it's because in the US members are the primary source of funding, whereas here the nominal fee is small compared to funds from the Warsaw and Polish governments and other sources.
The Rabbi is fascinating. He speaks fluent Polish as well as native English. and has both Conservative and Orthodox smicha. Perhaps most fascinating, and spooky, was that he was invited to be on the plane with late Polish President in April but did not fly, because it was Shabbat, saving his life. The interview he gave after the tragedy is worth reading.
All in all, a fascinating city, and definitely merits a visit.