Chiming in here. I love my New LC and SC razors. Smooth, efficient and pretty mild and I get 2 pass near BBS shaves every time. I consider the NEW to be the pinnacle of 3 piece razor development. I like my Slim as well, but have not used it as much. The longer handle seems to change my approach for some reason and I haven't gotten as close of shaves consistently.
Good point about the handle. I think that's a key factor. For example, I have a long handle black beauty and I have just never gotten comfortable with it. It's a great razor, but I'm not consistent with the angle because of the length of the handle. If I were to use it on a regular basis, I might get great shaves, but I like the slim better. Point is, geometry is a factor and curvature of the head and length of the handle all come into play.
I agree geometry plays a significant point. I also wonder if New holds the blade more rigidly than the TTO Slim.
I tried again yesterday morning. I did my first pass with my slim and set it down and did the remaining 2 passes with my New. In my hands the slim doesn't compare. Even when I try and adjust the angles.