Better go for the M4 Pro right away. I bought the base model of the M4, and I am not really happy with it. From the start I suffered from freezes and crashes. 16GB of RAM is simply not enough if you work with LM Studio or want to run a virtual PC. In addition, I had to completely reinstall the system because it suddenly could not connect to iCloud anymore. This meant that I could not access my account (except via Safari). In retrospect, I would have preferred to go for the M4 Pro right away.
That said, the design, screen and sound are top quality. The battery life is generally good, although this depends a lot on your usage. With normal use it lasts a long time, but with intensive tasks, such as gaming, I had it empty in about 3 hours.