Should I take the ACT with or without writing? What are some pros and cons of either choice?
Take it with writing if the colleges you are interested in require that - look at their websites. Don’t bother if they don’t. Very few colleges still require it.
Check the requirements of the schools you’ll be applying to. Some require you take the writing portion. DS had one school on his list that it was “Recommended” so he did it, but I wish he would have skipped it. He did awful on it both times, and I’m guessing that looks worse than just not taking it. There’s no way you can skip sending the writing score either. It’s all or nothing.
The UC system requires it for sure.
If the schools you want to apply to require it then you need to do the essay.