I have never updated via the Combo, although many people recommend it. In all the years that I have been doing this, I have never had an issue.
I've always used Combos to update, but my understanding is that the updates that come from the App Store are tailored to your specific Mac, and that would seem to make them the preferred way to go, reserving Combos for emergency use.
The new Great Equalizer is the SEND button.
In Memory of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire
