I agree. VFS will cost more, but you will get your passports returned quicker and (depending on where you live) you can have them delivered right to your door instead of having to pick it up at the courier's distribution warehouse, as is my case.
As far as I'm aware, the consulate/VFS uses 2GO exclusively for all returns.
In my opinion, it's worth the extra Pesos to have the ability to track the application from departure to arrival, and the added sense of security when the passports are being sent from place to place. The consulate encourages using the VAC for faster processing and logistical handling.
If you don't want to use the VAC, I would suggest 2GO.