Hello! i have had many problems with after effects and i was just going to make a visualiser with it.
Here are my pros and cons:
Easy to make a visualiser
Crashing on first startup
Losing project due to no auto recovery
Audio changing pitch and speed while playing in preview
Not very easy to use
Not easy to make a time counter
I am not using this as my main program because Vegas Pro is much more reliable
You have to spend some time to learn how to use all of the thousands of switches in AE. There are a bunch of ways to create music visualizers out there. Personally I think that 99.9% of them are boring and not creative. I'd put AE's music visualizer in that category.
If you don't want to spend the time to learn how to use AE, how previews work, how to make your system compatible with AE, and how to manipulate the controls you're going to be like someone who is forced to fly an airplane without any instruction. You may be able to keep it straight and level for a while, but you are probably going to break something when you try and land.
My suggestion would be to make sure AE is up to date and your system is compatible, then start here to learn how AE works: Basic AE
After Effects is a program designed to produce effects and animations that you cannot do in a non linear editor. It is powerful enough to recreate any composite or effect you have ever seen in a movie so there are a lot of switches you need to find and figure out how to use.