When I first heard of Shimano reversing the spring of their rear derraileurs I thought "This is the stupidest idea ever" Yet another example of Shimano becoming Shimano-soft. Then I unwittingly got stuck with an XT low-normal derrraileur, and after a month of using it I have to reluctantly admit, it actually is better. I'm using a SRAM cassette, and on any shifts involving more than 3 cogs at a time, the reverse design is actually faster. It's especially noticable when you have to do a big shift eg. high gear down a river bank, with only a second or two across the water to shift to your easiest gear to get up the other side of the river bank. My old deore could never make it to the largest cog in time, but the reverse spring XT did it with time to spare.