HuskyPup - 9:31 am on Feb 4, 2011 (gmt 0)
^^^ For all the above reasons ^^^
I do occasionally use the new one if there's something specific I want to drill down to but mostly it's all about speed, the old interface tells me mostly everything I need to know and I know where to find it within a click or two.
I had to do something the other day and I honestly couldn't find it in the new one even though I really tried.
If you made it the default I wouldn't use it half as much...maybe they would make you a saving?