MTP abbreviation stands for “Media Transfer Protocol.” This connection mode is more universal in comparison to ADB since it allows connecting not solely Android devices, but many other ones as well, like mp3 players or digital cameras.
Though connecting a device via MTP doesn't require advanced skills like activating Developer options, for the majority of modern Android devices you will have to choose the “File transfer” option in the pop-up window on your device screen, each time you connect a device to your Mac via USB cable.
MTP mode makes browsing the device's storage very simple. When mounted to Mac via this protocol, the device exposes the list of files and directories to a computer, displaying separately the internal phone memory data and SD card contents (if available) in different folders. Read more about how the disk contents is organized in different modes in FAQ.
However, the system files are hidden and can’t be modified. So the best option to pull the hidden contents of the device storage would be unblocking USB debugging mode in ADB mode.
As MTP in its essence is not a multi-stream protocol, data transfer can be really dog-slow or even unresponsive sometimes. So if you need to transfer many files from your device, use ADB to get the maximum data throughput.
Since MTP (unlike USB mass storage) has been built to allow exclusively a single operation simultaneously, no other operation can be carried out until the previous one is accomplished. In this way, MTP works like a non-parallel transactional file system which means that one cannot implement read and write commands at the same time. For example, in MTP mode you won't be able to get the folder contents until the file copying operation is finished. The new command will be queued instead.
In MTP mode a phone cannot be accessed simultaneously by different services. So MacDroid may be prevented from accessing phone's files in case another app, iPhoto for example, is running. The way out could be switching off the conflicting services. Refer to FAQ for more details.
When a phone is connected to Mac in MTP mode, there might be issues with retrieving the folder's contents in case the folder contains a very large number of files. Refer to FAQ for more details.