Zentalquabula wrote:

Any of the standard themes: Sylvia, Dark, Clear, Elegant.

None of the ”modern” themes: Greydragon etc. This is because they create custom sizes on the fly, and that will kill a high traffic server.

not really... those pictures are created once so it's a problem you add lots of pictures during a high traffic

if you are planing to have a high traffic website, you have a budget and skilled people to understand technical stuff and makes performance tests.