The one thing we did inside the house before we moved in last year was replace the floors in the bathroom and the kitchen. I knew that it was something that would never get done once we were living there. Both rooms had old vinyl flooring over the original linoleum and in the bathroom both were in super bad shape, discolored, rotting, generally yucky. The kitchen had some 50+ year old vinyl that was super heavy duty, but split and peeling up at the seams.
Paul started the task of pulling up the old flooring, which in the bathroom turned out to be rather difficult. The linoleum was rotted and crumbling so it came up in tiny pieces and the tar paper backing was glued on there tight. Like most bathrooms I've seen the floor under the toilet was in the worst shape. I knew there would be issues since there was substantial water damage, missing plaster and rotten lathe, in the basement under the bathroom. So it shouldn't have been a surprise that the sub-floor and the sub-sub-floor were both completely disintegrating as well as part of the wall in the corner. It's kind of a miracle the toilet didn't fall through the floor actually since there wasn't much support. See the drain pipe for the toilet? This picture is from before we removed most of the rotted sub-floor and wall. There just wasn't anything there. My dad helped us out with fixing the floor with bondo, a 2x8 and some chip board.
After the sub-floor was structurally sound, a layer of cement board and ceramic tile went down. We went with the octagon and dot Dal tile instead of hex tile because Paul liked it better--I think that's a good enough reason. We also used a grey grout instead of white and I like the contrast with the white field tiles and will probably do the same with the wall tiles, and it avoids the future issues of dirty looking white grout everyone complains about. It took over a week (two weeks?) to do this since we could only work Sunday-Tuesday nights or Saturday day.
We ordered the tile from a local tile shop and had excellent customer service. I know the same tile is also available at HD or Lowes but after ordering the kitchen tiles from there I'm loathe to special order anything there again.