I understand what you are asking, but it’s kind of like asking what’s the best way to get to New York. It depends on where you are starting and what vehicles you have at your disposal. So it’s kind of a subjective answer.
I did mine the manual way because I like to understand where things are going and what the process is to install it. I know linux fairly well, so it wasn’t difficult for me. That isn’t to say the other methods aren’t just as good. If you goal is to get HA up and running, pick the one that fits your knowledge level, and patience level.
All in one was the only way I got it running on a raspberry pi 3, it gave a few errors but they where easy to correct some needed an extra lib installed.
If you know linux/unix, then you won’t have any problems on the pi. It’s just a different flavor like redhat, umbuntu, debian, etc. And in any case, if you have questions, just ask out here. I’ve found that the people out here are usually pretty quick to answer, and very helpful.