It's just fun to sledge down the 3.1 km long trail. the trail can be pretty fast, depending on whether some parts are icy. In total, it's 330 meter difference in altitude that are sledged down. The top can be reached conveniently with the Üetliberg train leaving at the main station.
With fresh snow, a visit to the local mountain of Zurich is spectacular with or without sledging, but adding a bit of action never harms. Bring your own sledge or rent one at Uto Kulm, the restaurant at the top of the hill. Watch out: This place is not recommended for small kids.