Personally, I don't really use PinSound Studio to do my orchestrations except for one thing: game playback/simulation. You do all of your sound editing outside of that tool (see my guide - Audacity is your best friend for capturing and creating custom music/fx/etc.), but the one thing for me that was very useful was the game simulation. This helps me listed to my sound events for timing, loudness, etc. within the context of a game without having to run back and forth to the real pin to test.
The issue at this point is that the brothers can only do so much at once. They are in the middle of releasing their shakers and need programs developed for pins (I did the one for Getaway). In order to program the shaker, they had to come up with a new process and new software (i.e. PinSound Studio Pro). I'm sure that once things settle down then they will have time to add the playback feature into the new version, but only so many hours in the day, so to speak.
While you don't really need the tool to do a custom sound package, you do need it to do a shakerization. The new PSSP is awesome at doing this. It makes things very simple, and you can literally do a shaker routine in less that 5 minutes. Now, you'll spend much longer than that trying it on the real pin and making adjustments, but getting something basic done is quite simple and quick. The good news is that PinSound will actually include default shaker routines for games already done by community members. In this case you don't have to do anything to have the shaker work, or you could tweak the existing routine to your liking.