Hardware Canucks has recently reviewed both the Rampage V Extreme and Matrix GTX 980, awarding them both as 'Dam Good' hardware.
On the Matrix GTX 980:
"The ASUS GTX 980 Matrix is arguably one of the most eagerly-anticipated graphics cards to be launched this year and looking at raw numbers, there’s no denying the wait was worthwhile. However, in order to truly appreciate its full stable of features and abilities one needs to fall firmly within its target audience of enthusiasts.
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Allowing the Matrix to run free under air cooling gave us the first tantalizing glimpses of what ASUS has achieved. Core frequencies hit 1466MHz on a consistent basis and memory nearly achieved 8Gbps. It goes without saying that at those speeds performance was extended far beyond what a bone stock GTX 980 can hope to achieve..."
On the Rampage V Extreme (it's a huge and detailed review - a great read!)
"There's so much on this model that has been designed for and by overclockers. It features a Q-Code debug LED display, LN2 Mode jumper (helps remedy cold-boot bug during post at sub-zero temperatures), Slow Mode switch (drops the CPU multiplier to temporarily enhance system stability), power-on Start button, Reset button, MemOk! button (initiates memory compatibility tuning process), and thermal probe header. The two newest button additions are particularly ingenious. If you are overclocking and your system fails to post successfully, you no longer have to hit the CMOS Reset button. Instead you can now press the Safe Boot button and it will power off your system and then boot with default settings allowing you to modify the last configuration to fix the problem.
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The ProbeIt area features an assortment of actually useful voltage read points, which is something we can't say for most of the other motherboards we have reviewed thus far. It's impossible not to mention the OC Panel either, the cool monitoring and overclocking accessory that comes included with this model. This mighty gadget - that usually retails solo for $100 - has proven itself to be a fantastic addition to many overclockers toolbox, and ASUS have been doing a commendable job on ensuring compatibility across multiple platforms."