Yep, did it in November/December 2008 out of la Paz. It was still shorts and tee-shirt weather during the day and blankets provided were enough to stay comfortable at night. The highlight was swimming with the sea lions. Also, provisioning is great at the supermarkets in La Paz, so if you have the time do it yourself.
I've posted a detailed trip summary
for our 1 week charter from La Paz on my blog - bareboatingtheworld.com. It includes a mapped voyage log, pictures, and insights regarding getting there, food and drink, and other sailing stuff. Hope the info helps.
Bareboating the World