Both the Gigabyte GA-Z68X-UD7-B3 and G1.Sniper2 are IMO rip-off's to 99.99% of the Enthusiasts out there and the 'doodads' of the G1.Sniper2 help very very few.
I noticed your Corsair H100 post so my assumption is OC is your 'goal' and the best (2) Gigabyte MOBO's for the $-to-OC are Gigabyte GA-P67A-UD7-B3 and GA-Z68XP-UD5. Regarding Phases - yep to a point, if effectively used, do aide in lowering the vCore which lowers the CPU temps to better achieve a stable and obtainable high CPU OC. The returns are very diminishing with 12 Phases and higher.
The 8 Phase Gigabyte G1.Sniper2 would concern me if >4.5GHz is your 'goal' OC.
I know Gigabyte GA-P67A-UD7-B3, GA-Z68X-UD7-B3 and GA-Z68XP-UD5 ALL OC very well. I know the ASUS P8P67 PRO or P8Z68-V PRO (+ Deluxe versions), Maximus IV Extreme/z all OC very well.
The 8 Phase Gigabyte G1.Sniper2 with OC > 4.5GHz 'concerns' me that it's vCore might be higher than the ones that I listed. Keep in mind I am looking at averages and not the lowest or highest vCore -- a lot of that is luck of the SB CPU.
All the vCore to Phase studies that I've seen have a strong correlation to 12 and higher Phase MOBO's. If an engineer screwed-up than high or low the Phases won't over come the error.