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The "advantage" is only relevant to those horns. It can have various effects. You can use the steps to improve intonation, you can also use it to make an otherwise "stuffy" note clearer. Sometimes it is advertised as a way to make a medium bore instrument sound more like a large bore.

It is just another combination of the possible design philosophies that aren't better or worse than other well designed combinations, but give something for the marketing people to talk about! If you get a chance, play the horns and tell us what you experienced. I played a silver plated one - it sounds almost like a Xeno. Like every Yamaha instrument I have ever played, it was in tune and easy enough to play. The sound was nice, a little too aggressive for my personal preference.

The ads say greater spectrum of color, excellent intonation, easy blow - don't all trumpet ads claim this?

The only real specification that is worth registering is: what comes out of the bell when I play it?!

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