The autofocus is not reliable at all. That among a few other features (e.g. battery life, internal intervalometer missing, poorer color balance, etc.) is why I would recommend investing in a newer a7r model if money is no issue. I usually use AF to get in a general range of sharpness and then go manual from there to dial it in a bit more. Nevertheless, you can easily get around the pitfalls of the a7rii.