I recently bought a month pass on GroupOn ($25) for the Dovercourt/Bloor location.
I've been twice and both times the instructor was 15 minutes late yet still ended the class at 7pm after 45 minutes (rather than an hour). The instructor spends a lot of time talking and laughing with her friends during the class. Her cueing needs work ... she doesn't count you down to let you know she's changing moves but just does them, which leaves you struggling to catch up. Sometimes she stops to take a drink or wipe with a towel while we're still doing a routine and rather than jumping in where we are, she'll start the moves but be off in the timing.
Though she seems like a nice person, it's not a professional or enjoyable class and I won't be back. I taught aerobics for three years so maybe I'm picky because I know about cueing and mirroring.
On the plus side, I'd forgotten how much I enjoy Zumba classes (it's a fun workout) and will be looking for another class to join.