if your into gaming your better off a some point in getting a new mb and cpu combo. if you go with a skylake cpu your going to need ddr4 ram with the upgrade. go with a h97 mb still use your older ddr3 ram.
Replacing a motherboard is a sideways move so far as performance goes.
What is your cpu and gpu?
What is your objective in going ITX? A lan box perhaps?
Intel Core i3-2100 3.1GHz 3 MB Cache, GeForce GTX 650 1GB GDDR5 & I just want a smaller systerm... I have a SG01 & it is a bit big IMO, if thay had a mATX SG05 or 08 I would do that...