Much has already been written about all other aspects of Hyundai Santro Xing. Pretty well dissected...even adverse comments on the looks - going as far as to compare it with autorickshaw!! (I guess they really dont make glasses these days as well as they did in the golden yesteryears :-))
So I will restrict my comments to its performance on a highway... Posted in small Haridwar with Coke, just out of sheer boredom, I used to do do the over 200 KMs Haridwar-Delhi stretch every week-end. Its and ideal route - some world-bank aided super miles, puncutated by moons craters...infested by crazed truckers, sone-age vehicles, and mind-boggling moving contraptions.
I bought my car then, learnt driving on that road, and became proficient in navigating it at high speed. Full marks, straight A+ to Xing.
Handling: is superb. Rock-steady on straights and takes corners comfortably. The high CG scare is a state of mind - all cars mandatorily clear the topple test.
Stability: never a problem. I have done 140 once (will never do again, its crazy to try this in any car) and did feel the car going out of control. Needless to say I regularly left everyone behind, except for some suicidal maniacs mandatorily driving a Qualis. The Hydraulic power steering behaves admirably even at high speeds.
Comfort: Performed well in bad stretches and high clearance meant navigating out of all difficult terrains. The high seating position does mean that your foot angles more and tends to cramp after a 3-4 hours of continuous driving.
I have driven many other vehicles on the same road after that, including a Scorpio, but apart from less rocking at high speed due to (vastly) increased weight, Xing kept on par on every other parameter. I am glad I bought it, and look forward to another drive though I am stationed in Gurgaon now.
~ vik