The thing is 20 years ago the biggest tile you would probably come across was a 8x6 or at a push 8x8, the only good adhesive was bal wall or ctf which both needed battens, we were still laying floors in semi-dry screeds, so the demand for tools and adhesives have grown with the industry, as for adhesives and grouts i think for most straight forward tiling jobs they all stand up well, its when you start pushing the boundries with slate/stone and porcelain that some of the lesser known brands come up short, the experience I had a few years ago with laying a slate floor with howtex rapid+admix is that the slate debonded clean from the adhesive bed, called the rep in he layed a slate down himself came back 2 days and we just lifted it clean of the floor, the upshot was we changed to bal rapidset flex and never had a problem, the reason for the debonding was a high mineral oil content in the slate which the howtex just couldn't cope with, but getting back to the last question, you can do the best tiling job and rush the grouting and ruin it so this guy probably just took his time, its all in the finish.
