I was a bit hesitant with trying the extra column of tiles when I got Cyan, but I decided to try it out for a while and I soon got to really like it. I then went on an old screenshot of my start layout before Cyan - and I was taken aback a bit by how big the tiles seemed and how much space they used up before, it seemed an inefficient use of the 4.5" of screen. I haven't had a problem with the size of the small tiles so far, although the decrease in size did throw me a bit at the beginning. Plus, the ability to have more wide tiles, without them taking up about 1/4 of the screen, means I can use my live tiles a bit better, with more content on them. I can't see me going back to the two-column set-up again.
It did take me a week or two to get fully used to it - the start layout is the most personal and well-used part of a Windows Phone, so naturally a radical change like this can seem a bit odd at first.