I am trying to decide on one of these pens. I know that I have to make up my own mind but would like your views on one or both of the pens. Does anyone own or have tried both? What are the differences? Similarities? Thanks.

I have both, and they are quite different. First, you have to open the blind cap of the 823 to write. Otherwise, the inkflow is stopped and the pen will dry. I am sure the 823 takes more ink thanks to the filling mechanism. The nibs on both pens are great. My 823 has a medium nib (that is, the one I am using regularly, the other one in the box has a broad nib), the 845 has a fine nib. The nib on the 823 is monotone, the one on the 845 is duotone. A fine nib is really fine, this is a Japanese pen. In the end, I am a sucker for urushi lacquerware. It shines so beautifully. If possible, get the both, with different nibs so that you can use them for different occasions. Ruud

I have an 823 with a Bold nib. It is very very stiff but very very very smooth. It writes a sort of Western Medium line. If you like a stiff and smooth nib, then you would probably like the Bold nib---at least the one I have tried.

As rhk mentioned above, you have to unscrew the blindcap to write. Then you have to screw it down again when you finish. Then you have to open it back up. It is really no big deal, but if you think this would bug you or if you think you do not want to write with a pen with the blindcap unscrewed a bit, then maybe this is a consideration.

Other possible drawback to the 823 is that unless the nib unscrews, it might be harder to lubricate the piston chamber if you needed to do so than it would be to do the same on, say, a Pelikan or Aurora.

Generally I think it is a nice pen and a good writer. I really like the large Pilot nib.

I do not have the 845 so I can not really offer any comparison. I sure would not mind having an 845! Either pen will probably be great and easy to resell if you decide to do so. j