what a good sharpener for knifes (not a stone or stick)
Frankly, your best option outside of stones for a Carbonext gyuto is probably professional sharpening.
I'm not enamored of unpowered pull-through sharpeners like the chefs choice for harder knives (I believe the carbonext is moderately hard, though not very chippy) - it's easy to use, but still takes a lot of passes to sharpen a dull knife and doesn't produce especially fine results. I suspect that most people reviewing it on Amazon are using it for Western-made 'Asian' knives, which are typically softer than the Carbonext.
Powered sharpeners are seldom designed for Japanese knives and often don't play particularly well with their harder and more wear-resistant steel.
Devices like the EdgePro produce top notch results, but are expensive and aren't much faster than stones. Slower sometimes.
Carbide sharpeners (like the accusharp) don't normally work for harder knives, and besides they thicken the knife behind its edge and aren't set at the correct angle.
Set-angle rods like the Spyderco sharpmaker are set at too obtuse an angle, and take even longer than stones to sharpen a fully dull knife.
The Global minosharp is an interesting device, and it's gotten decent reviews on Amazon (for whatever that's worth). But I have no personal experience with it and as such can't give it a real recommendation for or against. I do know that Globals are typically a bit softer than the Carbonext, and also come (at least initially) with convex edges, so I'm not sure entirely what to expect from a sharpener designed for Global knives. If nothing else sounds like it meets your criteria, you could always test pilot one (and then come back and tell me how it works ;D )
That's leaving you with seeking out a pro. Hopefully one who happens to be on your way.
I will add that most people get faster at hand sharpening on stones the more they practice it. I can put a coarse or moderate grit edge on most dull knives inside 2 or 3 minutes if it doesn't need any repairs (there are a few extremely wear-resistant knives which take longer, as do knives that are dull-beyond-dull). Of course, finding that time to practice may be just as much of a problem. Also, if speed is a major concern, a coarse stone in the 240-500 grit range can significantly shorten the time it takes you to put the initial edge on a very dull knife. A 1000 grit stone works, but it's certainly not as fast.
The highest rated knife sharpener (both manual and electric were tested) for Asian knives is the Chef’s Choice Diamond Hone Asian Knife Sharpener, Model 463 for $39.99 shipped from Amazon.
A regular sharpener (one that creates a 20-degree angle on the blade) will work for your knife, but for the very best edge and one that's true to what the knife was intended to have (a 15-degree angle), a sharpener specifically designed to sharpen Asian knives is your best choice.
The great news is that of all the sharpeners Cook's Illustrated tested, which included both electric and manual, their highest rated one is electric and is a fraction of the cost of the electric models tested.
I assume that you don't want to use a sharpening flat stone nor a sharpening rod. If you have money, then you can use the Edge Pro Apex Pro.
Technically speaking, it isn't much faster than a sharpening stone, but it is much easier to use. It is my belief that many people who claim that they don't have time to sharpening their knives by using a sharpening stone, are really saying that they don't have time to learn (which can take weeks).
The cheaper alternative is to use what Sid Post has suggested. Something like the Spyderco Sharpmaker.
By the way, if I am not mistaken, you got yourself a CarboNext gyuto, right? I have a Santoku version of it. Here are somethings like about and there are something which I hope more of it. In my experience, you don't want to sharpening this knife more acute than 15 degree on both sides. The few times I tried, the knife cannot hold the 10 degree edge for long. On the other hand, it holds the 15 degree edge quiet well, and it feels (I cannot prove) less chippy than a VG-10 knife.
Preset ceramic rods will run 30 degrees which is a little more obtuse then the edge you want on a Gyuto. However, they are easy and quick to use. A diamond plate will cut quick if you free hand your knife sharpening (assuming this how you use your current stone).
I would start with a fine diamond plate and see how that works for you. Avoid the blade munchers on can openers and similar contraptions.