I find Opera waaaaay faster in use, simply as the programme is so much better designed. The actual initial page load time is actually a minor part of the browser experience. Even FF which simply copies all Opera's clever ideas is clumsy in use by comparison.
Though to get the best out of Opera, learn how it works and tweak the very customisable interface to suit yourself. As Opera does so many things that other browsers don't do, most people never even think to look for them.
Even little things like using the z+x keys to go back and fore and 1+2 to go betwen tabs are sorely missed when using browsers other than Opera. Plus when you go back, Opera goes back to where you were on page not just top of page and doesn't reload it either. Big time savers.