I down loaded it and was impressed by the cool topsite interface but am still using firefox 3 mainly because I am a developer and use the developer tools. Obviously I do use Safari for testing but really don’t see that it is that much faster even though it is suppose to be 4X faster at running javascript. I find the topsite interface appearing when clicking new tab actually slows down the seacrh process, guess this is comes down to user preference and haven’t fully tested it so maybe it can be configured.
Safari 4 is marketed as the world’s fastest & most innovative browser, for all 150 features check the Safari website or check out the review at crunchgear.com