I've worked in both PS and HTML for mockups.. in different team workflow enviros, sometimes out of necessity, sometimes as experiments, laziness etc.<p>Photoshop almost always produces more esthetically pleasing layouts. Its also a lot faster to knock out ideas. And if you have clients (not solo) its the only way to go.<p>When you work in HTML first its very easy to back yourself into a wall. You're constricted by boxes and CSS, and due to the difficulty making certain things work in CSS you're usually less apt to do something difficult, so you get very dry layouts.<p>Hacker News is a great example of a site that was designed in HTML haha. One giant column, no chrome, no styling of almost anything. Easy in CSS, hideous on the eyes...