The Dale Chihuly Art Exhibit was beautiful - it's definitely worth it to see the exhibit at night! The Chihuly features were installed in the garden among beautiful flowers and cacti. Great place to take out-of-towners.
We went on a Saturday night - early in the evening it was packed, but the crowds thinned out as it got later.
If you get the evening tickets, get there early to see the exhibit in the daylight, during sunset, and at night - the way the glass is lit up at night is gorgeous. Get tickets in advance online to skip the lines (the Chihuly exhibit is there through May) and dress for the weather.