I had one of those and - speaking personally - I found that the bare-metal grip was not friendly to my palm, so I fitted a wooden handle to it.
Also, in that configuration, it is 'handed', in that it has a flat sided blade on the left , so that when you hold it is correctly it is solely for a right-handed use. It's a contortion to use it the other way round.
There are Japanese versions available that has a Vee shaped cutting section where presentation angle can be reversed, left or right. Again, a good tool, but the blade sectional thickness is rather chunky, resulting in a one-sided bruise distortion on the scribed cut, it also limits the depth of your cut if you need something deeper to chisel into. The comfort aspect is the same as the other one..... it needs a handle to be comfortable, I think.
Whatever the blade shape, the size should suit the work you're doing, but it's not crucial.... about 1/2 inch wide will do most things.
However, for the past 20 odd years I have used an old chip carving knife, sharpened on one side, like the Japanese job, so that the flat side is on the left. It's advantage for me is that its blade is a lot thinner and it can hold a sharp point, giving a more vertical and well-defined cut on the 'good' side and less bruising on the waste. It's disadvantage, if that's the case, is that it needs a more frequent touch up on a stone and strop.... but just a couple of strokes and it's ready again.
The one thing that will happen is that when you get the right knife for your work and your style you'll always reach for the same tool, every time. The process is a bit evolutionary in some ways; you'll probably go through a few versions until you end up with what you like.
good luck.....