Quoting for a huge ensuite with large format black titanium glazed porcelain (titanium powder in the glaze), textured like rhino knees. I agreed to mitre all corners which included 6 windows, gerberit frame, and two other full length boxes.
One wall used the same tile but in strip mosaic - still had to mitre round two windows.
I reckoned on two weeks and quoted accordingly.
Took me three and I just about cut even but a deal is a deal so I stuck it out and the end result was so satisfying the pain was worth it. (and another three bathrooms later in the same house I made my money on ;-)