Let me give you a bit of insight on my latest project:
http://dreitagewoche.de
It is a weekly updated, hand crafted event calendar for Hamburg in Germany. Its team looks for the most appealing events every week and collects them for the three days of the week that really matter: thursday, friday and saturday. It features parties, exhibitions, concerts, festivals, theatre and everything else a bit of the mainstream.
On the technical part (it uses PW 2.3):
Single events can occur on multiple dates and support a link to a location (page) with Google Map coordinates. Beside events we support blog-like entries and regular pages and other stuff. Events are displayed based on their date, showing up in an archive when they aren't up to date anymore. This method also allows for a custom preview of all upcoming entries for the editors.
I make use of template caching which speeds up the page remarkably. Beside that I am using some modules, including twitter feed, soundcloud embed, vimeo & youtube embeds.
The backend is modified using admin custom pages module which allows me to tailor pages showing only upcoming events or locations. With around 30 pages added every week this was crucial.
Overall I am very pleased with PW: It performs well, is easy to develop even with nested data and is fast and intuitive enough on the backend. And a full deployment means basically just a few clicks and a coffee while it is uploading.
One thing that did trip me was customizing the backend and actually the obvious need to do it. With hundreds of pages the normal view is not as helpful as I thought. The module I mentioned did help a lot, without that I would have been in trouble. I am looking forward to using PW 2.4 on a project like this and how it accomplishes those challenges.
Let me know what you think, especially about tailoring the backend and dealing with lots of pages. I attached a screenshot of our backend (it is 2.3 and a modified backend theme, based on ergo theme)
Cheers!