I am using a Fujitsu Q550 Tablet PC with Windows 7 32 Bit OS. The Pen Input works fine with Windows-Journal.
When using xournal, the pen input speed is too slow, that results in bad looking or not understandable hand-written text,
The PC is using the N-Trig drivers and it seems for me that Microsoft has some better access to the drivers than xournal.
That's my feeling why ther is such a guge performance loss from Windows Journal to xournal.
So it would make sense to spend some time to investigate and fix the root cause for the pen performance problem.
I hope that one of the next Linux distributions will run on the Fujitsu Q550 Tablet PC and the performance will be better if using xournal in combination with a Linux OS.