I researched this razor quite a bit before buying it. I was looking to see if I would like the kamisori style razor so I would have more visibility of my face without having the scales of a European style straight razor design blocking my view when shaving the left side of my face with my right hand (for example). I also wanted to see if I would like the Feather Artist Club DX style blade holder before I spent a lot of money on one (I had already researched and decided that I liked the head of the Feather Artist Club DX better than the Feather Artist Club SS razor).
From interactions with people who owned both the Feather Artist Club DX and the CJB, I was told that the blade holder was identical between the CJB and the Feather Artist Club DX. The only difference was that the Feather was said to have a better finish. I found no issues with the fit or finish of the CJB. There were no raised places in the blade holder to cause any blade gaps (but if there were, I would have used some 400 grit sandpaper to smooth it out). The blade fit perfectly in the blade holder with no gaps.
The handle is a rubberized plastic from what I can tell. If you decide you do not like the kamisori style razor, I read that you can peel the rubberized coating off of the CJB and you will find a hole at the end of the tang where you could attach a set of scales. That would make this razor more of the European style Feather Artist Club DX (at a fraction of the price).
I found the handle to be a little slippery with wet hands but this was solved by wetting my fingers and rubbing them on an alum block before using the razor.
So far, I have used Kai Captain Titan Mild blades as well as Schick injector blades (which also work in this razor). I plan to try out Feather ProGuard blades next as those are said to have more of a traditional straight razor feel.
The CJB blade holder suffers from the same issue as the Feather Artist Club DX with stiction (I believe that is the term). The blade holder is very big with a completely flat surface on both sides. When you shave, if your angle is too flat and your later is not really slick, the razor will get 'stuck' in the lather mid stroke and you will have to pull the razor off your face and start again. I am sure if you found the right soap with the right slickness and watched your angle, you could get an amazing shave with this razor. I am also sure that you would need to use this razor regularly to learn how to use it as it demands a different technique than with other shavette style razors or DE razors.
I did not find the angle (where you did not get stiction) to be comfortable. I found the blade to be in angle that felt harsh on my face. I much prefer the Irving Barber Company (IBC) shavette style razor to the CJB as I can get a shallower angle that is not harsh and run into stiction much less than with the CJB. The IBC can take the same blades as the CJB as well as half DE blades.
It does take concentration to use the CJB or you will get cut. That said, I plan to keep the CJB and work with it. I am sure that I just need more practice to make it work well for me.