Turntable set up- How easy is it

I wouldn't do final arm adjustment until your the cartridge had been fully burnt-in, that's at least 100 hours but possibly more. 100 hours is a kind of universal number, more or less. My Grado phones was not fully burnt-in after 100 hours but probably 90% so. The same with Purist Audio interconnects. But both kept improving after 100 hours. Cartridge is something different but still..
I would give it 200 hours. Now if you are going to adjust VTA and anti-skating for each record as some do - you got a problem of being frustrated and busy all the time.

Inna, according to Soundsmith, the mechanism of cartridge break-in is rather disconcerting.

They say that a cartridge breaks in by twisting its guts to accommodate an imperfect installation. Certainly my Koetsu has not changed much, except for the "magic" when I got the final minuscule correction just right.

If Soundsmith is right, and they are, after all, a cartridge manufacturer and rebuilder, then it follows that adjustment should be continuous until you get the magic.

We have better hearing and more objectivity than Peter. Just kidding. 

There is a thread here, most people agree that 30-50 hours are needed for certain. Some think 100. I am trying to save the man a lot of time and effort. Make the initial adjustments to cover the basics, then wait for 200 hours and spend a day to get it right. Not too much work. But if he wants to make it truly spectacular - align the cartridge by ear. This might take couple of weeks, so what? I was kidding. I certainly am not going to do this, though it could be interesting. In this case you would be doing individual custom alignment.

I was brought up on the conventional wisdom too - 100 hours or so, but I never did understand the mechanism. It sounded a lot like a practice from WW2 where riflemen from US and UK would exchange a single round (.30-06 and .303), fire it, and find that their rifles shot better.

Then I heard the word from a manufacturer. Who would know more about cartridges breaking in than a manufacturer? Only a rebuilder. And Soundsmith is both. So I accept their considered opinion until I have very good reason to change.

Fiddly, yes, but worth it in longevity, I think.