If you want fast, I would go via Cancun. Since the actually turn off south of the Cancun airport, you avoid all the Cancun congestion and its mostly toll road. The toll roads in Mexico, however, are very expensive.
Thanks. I'll go via Cancun, then. Tolls do seem a bit excessive as well as gas prices. However, the bus tickets for 3 people will run about the same (it's $195 each way per person from Cancun).
Are you certain? What happens to a maid from Xpu-Ha when she goes home for a weekend?
I would check that price.
I guess his $195 was meant to be 195MN.