6 of one, half dozen of another....
"Best method of recording individual channels to a multitrack digital recorder is via direct outs on the mixer."
Not entirely true. Really, unless the mixers main outputs are transformer balanced, and you want the sound of the transformer to go to tape, there is going to be little difference between routing to the main buss and an aux send to feed the input of a multi-track machine. One or the other may provide you with more functionality in sending signal to tape and monitoring at the same time depending upon the capabilities of your mixer and how you like to do things. But both are going to sound the same in the end more or less.
The aux output is more then likely on an OP amp, and some don't like the sound of them compared to a transformer. They both I suppose have slight differences in sound, but you will be hard pressed to hear most of the time.
If the aux send is pre fader, you have the advantage of listening to the channel while recording, and you can mess with the channels fader all you want to do a monitor mix without effecting the aux output. This Pre Fader Aux send may or may not be post EQ, something you should check out if you intend to use the channels EQ while recording. If it is a Post fader aux send, then the fader WILL effect the aux output, and will be Post EQ. Most consoles have at least one Pre and one Post aux send on each channel. The more expensive consoles have more aux sends, and the even better ones will let you select whether these sends are Pre or Post fader. Whether ANY aux send if Pre or Post EQ is something you should obviously check.
Anyway, in this case, there is little difference.
If I was going to say what would be the BEST output from a console to use for feeding a multi-track recorders input, I would say either a channels Direct Out if it has one, or, the Send of the channles insert. These would both provide the shortest signal route and cleanest signal and are free from an extra gain stage.
Good luck.
Ed