Just to clarify. There is an important difference between unified memory, meaning accessible by both CPU and GPU, and regular RAM that is only accessible by CPU.
The presence of unified memory does not necessarily make a system better. It’s a trade off: the M-series systems have high memory bandwidth thanks to the large number of memory channels, and the integrated GPUs are faster than most others. But you can’t swap in a faster GPU, and when using large LLMs even a Mac Studio is quite slow compared to using discrete GPUs.