There was a really good speech by our Greens government in relation to the Australian budget, but woe she was talking at around 150. Shorthand usefulness is highly handicapped even at 100 even at 120.
I suggest to learn a system that has a high ceiling speed, because you don't want to be limited to below verbatim speeds. At least with anni or pre-anni I know that I have the capability of reaching that speed, but if you're limiting yourself to never take proper verbatim, well then you will rarely find yourself in a position where someone wants to dictate to you only, and will always be stuck with an inability to keep up.
My rambling has sort of turned into a pro-older systems argument, but I think its good to set your sights high. In this age, the most practical thing you can do with your shorthand, is take meeting notes, to record speeches at gatherings where no one has thought important enough to take a tape recorders (which is most speeches in fact -- and sometimes those speeches might be cool to post in a company or school newspaper, that would get you in good with your colleagues as well)
Of course I have been post-poning my engineering homework for the last hour, while taking this speech down. Taking dictation for a long time gets you on a bit of a high -- thats probably why I'm typing a whole essay right now.