The Quad Cortex would undoubtably give some satisfactory emulations of what any guitarist needs at any given time, but skill and talent are needed to get the best of the £1500 that you will pay to own it. Please don't take that statement lightly, because without skill and talent it could sound awful.
I have had the earlier, but very similar Helix as I have already said and it's just as expensive, in fact they are now arguing which is better between the two.
I ditched it after the thing crashed, I cannot have stuff failing mid show. I went back to my Vox ToneLab LE and also enjoy my Zoom G5n (the Zoom Gx3 is just as good) and I continue to use the Zoom despite owning the magnificent TVS3, Atlantis and Meazzi machines. Why ? because the Zoom and Vox Tonelab do the job with no fuss and are inexpensive by comparison. I will use my prize assets at selected gigs, but our weekly pub gig doesn't qualify for that.
My recent purchase of the Spark now looks a magnificent piece of business at £230, as I can get the exact amp sounds required, be it AC30, Matchless, Mesa Boogie, Fender Deluxe/Twin, Marshall, Orange - ANY, at superb accuracy as well as being able to DI into our mixer or my studio. As I've said already, the on board FX are excellent for chorus / tremolo / fuzz etc and the only thing I would add is my TVS3 if I wanted perfection.
It is not likely that I will be able to do a demo on the Quad Cortex, as I would need it here to programme and test, so we're stuck with the YouTube demos for now, but I won't be losing any sleep, as it's just another very expensive gadget that has hit the market featuring the latest Hi Tech available that we have had on our computers for ages. Basically, it's the stuff you buy for the computer in the form of 'plug ins' that has been 'boxed' and re-sold as hardware and as I have already outlined, many will not be able to understand what's needed to make it 'sing'. For 99% of people on this site, I would not recommend buying it.