Remember also that people have different fonts, font settings, and resolution sizes. And Safari has this weird... Safari font system thing going on.
exactly the way I designed the site in Photoshop.
It may be a nice thing to strive for, but browsers can't really compare to Photoshop... mainly because browsers have traditionally sucked with graphics and lettering, and because users have a lot of control (even when they don't know this) while people have little to no control when looking at something made in PS.
Compare to print, where someone can set how everyone sees a billboard. The billboard's the same size for everyone. It has the same fonts. It has the same colours.
Put that on a web page, and suddenly the size, font and colours are whatever people have sitting around on their OS, what they've set, what their windowing system has set.
You may already be aware of this, but I had to say it. I recently had some trouble on the forums because I downloaded a font imitation which didn't come with bold... took me a while to figure out why stuff wasn't working right suddenly : )