How much "fine tuning" did you do or have you done to the adams arms system itself(excluding buffers, buffer springs, roller cam pin)?

    I made sure to space the piston from the gas block and, insured alignment of the gas block, op rod and, barrel nut.  I also took time to confirm my op rod was striking the bolt squarely after everything was aligned. Took me longer than 30 minutes...  I only had about 300 rounds down range before I had to send my rail back to the manufacture but, the gun has functioned perfectly so far.

     What extra has anyone else done; how long did install take?

you covered the 2 most important checks, the op rod gap and the alignment of the gas block. Some extra checks i made was to make sure the new carrier moves freely inside my upper receiver and into the buffer tube smoothly.

Fine tuning? None.

I made sure that the gas block was aligned properly, but that was it. Everything else aligned OK.

The install took me about 10 minutes. I have shot 920 rounds without issue.

One thing I did for my pistol install was use a allen wrench just smaller than the gas hole on the barrel to make sure the block and gas hole are aligned before I tightened down the block.  of course the ole eye ball alignment, but when I put the rail on small tweaking with the block.