After using a the Carbonext for a couple of months now, I realized that there are many thing that I did not consider when making that purchase. Things that I did not think was a important and things that might not be apparent when I made my first purchase. At the time of the my purchase I was so eager to get a decent J-knives for a decent price that I only look at the steel type and forget the rest.
Handle are very important to a knife. Make sure that it is comfortable to hold in the hand. Thing you need to consider is the material of the handle. When holding does it feel somewhat cold to warm. The shape of the handle is another consideration. Is it too square? Does the manufacturer need to rounded the handle some more. Would you prefer a wa or a yo handle, octagon or a D-sharp handle?
Grind and Shape
Another thing that need to watch out for is the grind and the shape of the blade. Your style of cutting might not goes so well with the geometry of the blade. Some might prefer a narrower and straighter edge, while other like to have a large curve to the blade.
Weight and Balance
This is another something that you might also consider. Heavier knife can help you cut the food, but too heavy it might not suit your style of cutting. The balance of the knife is also very important. Some like to have the balance slightly forward, while other like to have it just on bolster.
If you are comfortable with 240mm, don't get a 210mm or 270mm. Unless you feel the need of wanting a larger/smaller knife, stay at your comfortable size.
You have to consider the overall package and not just the steel type or just a certain other element. A well made knife is like Apple computer, the overall package is very good, but the a certain part alone might not wow anyone.
I am not regretting my Carbonext purchase, I am very satisfied with my purchase. But there are some part of the knife that only after using it you wish they are different. I have to tweak how I cut with it to get the best performance/comfort, but that could just be I my lack of still. In the end I have to change my style to suit the knife, not buying a knife to suit my style.