The main benefit is that it incorporates indexing into its directory system, so that searching files is fast. This has allowed me to adopt the google philosophy of "search, don't sort" which has saved me tons of time. Of course google desktop allowed you to do that in Windows XP, but this is just neater. After years of developing careful file saving habits (starting with our first DOS based x286 back when I was 10 or so), it is still nice to not have to worry so much any more. (I still am nostalgic sometimes for the abbreviations I developed back when file names were limited to 8 letters)
The other neat thing I discovered recently is that they now seem to incorporate some kind of "smart sorting" algorithm when you alphabetize a directory's contents. If you look at the picture, the files are sorted as:
While this is not strictly alphabetical (lecture10 should come after lecture1 and before lecture2) it is far more useful.
I used to be more diligent in naming things lecture01 and lecture02 to avoid this problem.
I used to worry when software tries to be "smart" and try to do things for me, because when software is smart, it makes it harder for me to be smart, and forces me to be lazy and stupid and just accept what it is doing for me. In this case, when I ask it to alphabetize, it doesn't really alphabetize, but instead tries to guess what I intend. But in this subtle way, I am quite pleased.
Google, too. I used to appreciate the elegance of google's original pagerank where sites were ranked based on how many other sites linked to it. It wasn't the perfect algorithm, but if you understood how it ranked pages, you could know its weaknesses, and could think for yourself how to be smart enough to circumvent them. Since it came out, google's search has adopted lots of proprietary algorithms that it hides from me, but on the whole, that's ok, because it works, so I don't mind being lazy.
Apple, though, goes too far in being "smart." It frustrates me that it thinks features like copy and paste and customization of just about anything on the iphone would be too confusing for me, and so it just decides what it think is best for me, instead of giving me a choice.
I guess it depends on personal preference. Hopefully there will always be room in the market for both.