The Lamy feels less scratchy than the Pilots, but I didn't really mind the scratchiness. The more important differences in the way it feels to me are that the Lamy's bigger size fits my hand better and lets me hold my fingers a little farther away from the tip (making inky fingers less likely), and its triangular cross-section gives me a more consistent orientation, so I find myself holding the pen the wrong way less often. The writing comes out less blotchy, with better control of the line weight, and I don't feel that I have to write as large to make it legible. There's also significantly less bleed-through on the Moleskine square-ruled paper I've been using, although it's still nonzero.
I still don't know if these pens are more reliable in the air, but on the whole I'd say this is a big step up in writing quality.