I owned an '03 XS Premium, which I traded for the '10. I love the added room and new exterior styling. Things lost from the '03 - the handling is less nimble and more boat-like, there is less usable cabin storage space, the radio is not as good, the cabin fit and finishes are not nearly as nice as before, and the red display lights and small lettering for the steering wheel, radio and fan/heat/ac controls are annoying and hard to read (don't designers know that red is irritating??). I will keep this car for a long time; I just wish Subaru didn't cut so many corners on the interior.
The new body styling is great, and the added interior room is a big plus. I'm glad they kept the moonroof.
Improve the radio, change the dash/steering wheel controls (color and text size), better location for the mp3 input, more attention to cabin fit and finish in general.