I've seen two ways of beating time, and I'm not sure if there's a clear better choice. One way is for the ictus to always be in the same spot in front of you, with a followthrough to prepare for the next beat. The other is for the ictus to be at the bottom of each beat, widely separated. Do people have preferences here, or just "whatever the heck we can actually follow"? :-)
When someone is following a conductor, the location of the ictus is not so important as the direction of movement of the tip. This is going to seem counterintuitive, but the direction of movement is consistent with both methods, and I've known conductors to switch back and forth with the ensemble only noticing when inspecting the video afterwards. Think about this: the location of the ictus is a single point in time, and no one experiences anything in terms of single points of time, music especially. We experience music and time in motion.
What you are referring to is known as "Focal Point Conducting". There's an article you should read by Stewart Ross in the July 1996 issue of The Instrumentalist--"[Conductor's Clinic] The Conducting Focal Point: A Lesson from John Paynter".
I find horizontal motion very useful. It's hard to keep the ictus in the same place and capitalize on that usefulness, although I suppose it is possible.
Regardless, don't forget the musicians who are to your right and left. They won't see much in the way of horizontal motion unless you turn yourself to face them. They won't easily be able to see whether the second beat is aligned with your navel, your hip, or the outside edge of your music stand. All they can see is the height of the ictus and the vertical component of the motion in the gesture that prepared it.
In my experience, losing the players on the edge of the stage, or in the far corners of the pit, is a far more likely problem than anything to do with the positioning of the ictus. This happens if there is a similar amount of up-and-down motion on each beat. Keeping the baton (or hand) low, except on the downbeat, is therefore far more important than the horizontal position of the ictus. The character of the motion between each ictus and the next is also of great importance: that's where your expression lies, after all, as implied in NReilingh's helpful answer.
When I am following a conductor, I want to know which beat the conductor is beating, so a clearly-defined style with each ictus decently [not, perhaps, widely] spaced is crucial. If it's possible to misread which beat of the bar the conductor has reached (because each ictus is in the same place physically), it's possible to be beautifully on-the-beat on the wrong beat!
When I conduct, I conduct in the manner I like to follow, because I want to make everything easy for my singers.