While they were in town, I took my parents here on a Thursday afternoon to kill some time. Thursdays are free days at the SMoCA, and unless there's an exhibit there you really want to see, I'd say make that the day to go.
There really wasn't anything all that special there on my trip. Although I've heard they had some really cool things there in the past. The place is small, and it's a neat way to kill about 45 minutes if you're wandering around in old town. But if I had paid $7 to get in any other day, I would've felt robbed.