Just thought I'd throw out a question to anyone who knows typography.Is it ok to use half-point sizes for web fonts (e.g Verdana 10.5)?Does it slow rendering down? (this would matter to me since we are doing some very high frame rate display on the client).
Point size isn't reall so useful for the web, particularly for HTML/CSS (can't really speak for Flash or Silverlight). You can specify things in ems if you want a layout that can scale with font-size, but eventually things will all come back to pixels. Points is a measurement that's left over from print.
As far as I know most browsers will round decimal pixel sizes to a whole number, but the behaviour for rounding is not consistent.
I don't think it would affect performance, but for the above reasons I still would avoid it if you can.