Installing an American Autowire Classic update wiring harness

I hope you didn’t take my questions offensive, I was genuinely curious.

I have the AA highway 15 Universal that says it can wire the entire car and at times I think I am crazy to toss it to the side but I worry about actually being able to install it and things working properly. (I’m not the brightest bulb when it comes to this fixing old cars).
I was a little terrified to do it. I'm glad I did it my original harness was creating gremlins. My kit was the Ron Francis wr retro 95. Think yours would be more plug and play. Mine was a total rewire no key buzzer glove light none of that few things I have have to do that on my own now. Not a huge deal but it was a lot of work for sure and time. I only spent 350 not 1200.