Overall it was about a 2 1/2 hour journey including short connections. The connecting times can be a lot longer depending what time if day you are going. There were 3 or 4 trains per day and the route must go through Angermünde in order to be valid on this ticket. Train times can be found on the useful VBB site.
Another great option for heading to Poland from Berlin is the Brandeburg Ticket (also offered through the VBB transportation company) which is only 29 euros, is valid for unlimited travel in one day in the region and allows up to 5 people to travel together on one ticket! You can head to Stettin using the Brandeburg Ticket or go to Frankfurt (Oder) which is next to Słubice, Poland as another daytrip option.
Szczecin (Stettin) was really nice, with great architecture and yummy food. It could be a good daytrip from Berlin. We spent a few days in Szczecin and had a great time. There are some nice cafes along the riverfront area, with many boats coming and going.... enjoy!