long time no see!
Quick answer : It depends on the PDCH allocation algorithm.
in E/// : 100% PDCH is the standard value
in ALU : MAX PDCH can also be put to max value (= number of TCH/PDCH ts of the cell. What really matters is the max pdch high load.
… and then it depends on what you want to achieve. Better GoS to packet users, or less preemption from TCH, or more capacity for TCH, etc…