I asked the Uber web page for estimated cost from Puebla to Mexico City Centro and it was something like MXN1300-1600 on UberX. That's US$65-80, surprisingly cheap for door-to-door (taxi/bus/taxi would be around US$40 for 2 people and a lot more time and hassle).

Is there something funky about Uber's estimates in Mexico, or should we go for it? I realize traffic can be heavy around DF, but that's what the price range of the estimate covers, and a minute is less than 2 pesos so an extra hour in a traffic jam would be only US$6.

On the web one is warned not to take taxis between these cities since it is very expensive, but perhaps it is because city cabs charge out-of-city rates whereas Uber charges its regular rate even for intercity travel?

Presumably the driver won't mind being stuck in the wrong city without any guarantee of a fare back?