I have a cross cut sled, and only a 'standard' not upgraded miter gauge.
- For moderately large pieces I like the cross cut sled because it carries the piece with it, there is no "rotational force" (or drag from the table surface) on the piece being cut as I move the sled across the table. For really large pieces (longer than 4' from blade, wider than 1-2"), cuts become unwieldy for the sled and certainly for my miter gauge; neither offer enough lateral support for larger, longer, or heavier pieces.
- For small cutoffs and pieces, I definitely prefer the cross cut sled. I find it easier to keep piece in place before and after the cut (mostly because they are riding on a platform rather than sliding on the table surface).
Does the Incra gauge you have, or the one you are considering, have a platform that moves with the pieces? That would be a requirement for me if I were to consider an upgraded gauge.