I was going to hold off buying a TiBook until after Tokyo but it looks more likely that they will be released at NY. anyway all this means that i'll probably have to choose between the 550 & 667MHz TiBooks. i'm not sure who it was, but they mentioned that it really doesn't matter if a Mac is a few seconds faster than another. the real difference is if one renders in say, 5 hours and another in 3 hours. that got me thinking that i might not have to spend more cash and get the 667MHz TiBook. so my question is to anyone who has experience in 3D etc. when performing long and complex operations such as rendering, is there a big difference between the 550 & 667MHz TiBook? i.e. 30 minutes to an hour? does the extra system bus and MHz make a very big difference? sorry for the long post, thanks for reading!