Choosing Z170 Motherboards

Solution
Well, they're both using a 10-phase power delivery system for the CPU. So neither one will have problems overclocking. They both support DDR4 speeds above 3000MHz. The Asus board supports up to 3866MHz and the Gigabyte board supports up to 4000MHz. They're both using the full amount of PCIe lanes provided by the Z170 chipset. They both feature an M.2 connector, but the connector shares bandwidth with the X4 slot on the Asus model. The Gigabyte model also provides a U.2 connector, the Asus board does not. The Asus board provides onboard Bluetooth functionality, the Gigabyte board does not.

Given those differences, I can recommend both boards, although I'm leaning towards the Gigabyte model. However, if you need features that are on one...
Well, they're both using a 10-phase power delivery system for the CPU. So neither one will have problems overclocking. They both support DDR4 speeds above 3000MHz. The Asus board supports up to 3866MHz and the Gigabyte board supports up to 4000MHz. They're both using the full amount of PCIe lanes provided by the Z170 chipset. They both feature an M.2 connector, but the connector shares bandwidth with the X4 slot on the Asus model. The Gigabyte model also provides a U.2 connector, the Asus board does not. The Asus board provides onboard Bluetooth functionality, the Gigabyte board does not.

Given those differences, I can recommend both boards, although I'm leaning towards the Gigabyte model. However, if you need features that are on one board but not the other, then get that board.
 
Solution
I'm sorry, I provided wrong information on the Asus model. It provides two U.2 slots as well as an M.2 slot. The M.2 slot shares bandwidth with the PCIe X4 slot.

On the Gigabyte model, there's one M.2 slot and one U.2 slot. I don't think either one shares bandwidth with the expansion slots.
 
Unless you need onboard Bluetooth, I'd go with the Gigabyte model. It seems to have less proprietary features, there's less that can go wrong. Besides, I don't know anybody that actually uses all of the special features that come on Asus boards.

Advantages of Asus board: onboard Blutetooth, proprietary Asus features that literally nobody uses.

Advantages of Gigabyte board: faster RAM overclocking, more stable design.
 


It can do it without the use of additional devices. That ability is built into the motherboard.

This is not an Asus specific feature. Some other brands have boards that can do this as well. Not every Asus board can do this either. You need to read through the specifications to see what a board can and cannot do.