I've driven the Xb and I'm currently driving a Suzuki Ario (gt or xt or whatever the top of the line should be....the sporty one). I'm renting the Zuki 'cuz my transmission went to crap on my Tracker.

Here's why the box wins my vote.
a) Engine. a bit more pluck (even wihtout the available upgrades)
b) Interior. the zuki has a digital dash, but it doesn't seem to offer much real feedback that you wouldn't get from an analog. and I really liked the placement of guages on the box. the box seats are more comfortable and the dials and ***** are better placed.
c) Quality. yes, it is a rental, but at 20g's on the odometer, the zuki has some popping and rattling and crunching that just shouldn't be there. Won't happen with a Toyota product.

Don't get me wrong. I've LOVED my Tracker. It's been the best car I've ever had and the last 6 years have been trouble free. I'm taking this transmission repair cost because it's paid for and I'll get another 50,000 miles out of it without a sweat. But if you're looking at a new car in the catagory that the Scion and Zuki are in, MY OPINION is go with the Scion. I will be in a few years when I finally sell my Tracker.