For two-rail layouts in N or HO, the go-to choice for many years was Atlas. Their sectional track was what every beginner started with, and their flextrack opened up so many options for track planning different bends and curves that didn't fit into the rigid geometry of their snap track curves. Atlas also currently makes three-rail section track that looks incredible, complete with tie plates and spike details and properly shaped rail profiles. In fact, their O scale 2-rail track and 3-rail track are pretty much identical except for the middle third rail. See the picture below.
The problem is that to my eye the illusion is wrong. O scale 3-rail trains have oversize flanges, larger clearances underneath for the trucks and couplers to swivel, and other compromises. I fully concede that they will never be as realistic as their 2-rail companions. But, when properly weathered and ballasted it can look pretty good. I experimented with this a couple of years ago.
But when you stick a third rail onto a piece of track with prototypically spaced ties, rail size, and other track details such as the Atlas track, it all becomes very jumbled. The ties look too skinny and too close together. I am not sure if I can adequately explain it, but it is much too busy looking. Even if you paint the middle rail black (which I think also looks bad) it still stands out. Lionel Fasttrack has the same problem.
The best solution in my opinion is to use track that has larger ties spaced a bit further apart. This gives the middle rail more room to breathe and in my opinion it looks better overall. That is why I am using Gargraves track and Ross Custom Switches on my layout.