Where is the OTA update file downloaded and what is its name ?

Sorry but i really can't understand your question.

When there is an OTA update available you download the update file using the settings update utility. This file is then saved somewhere on the phone and applied after reboot in recovery mode.
I would like to know where this file is saved and its name.
On some phones it is saved in the /cache folder and named update.zip but this is not the case on the BV8000. This is why I ask

What's the reason behind this question? what you want to do?

See what has changed before applying the update.
Doing a factory reset and all the work needed thereafter (installing all apps ans setting them) is time consuming so I'd like to see if this is worth it.

ozolli wrote:

See what has changed before applying the update.
Doing a factory reset and all the work needed thereafter (installing all apps ans setting them) is time consuming so I'd like to see if this is worth it.

You don't have to apply the update as soon as it reaches you. Just wait a bit for the official changelog or for some users feedback on the forums and you'll be ok

Yeah I know, I know... But I'm curious and like to do things by myself and not wait for others instead