Matt Funamura

The Calicchio has a wider tonal spectrum than the yamaha. The Xeno is darker with a more pronounced midrange (not something I'm a big fan of). The Calicchio has a much more balanced tone from lows, mids, and highs and responds to my playing style more. I'm a jazz player primarily and I like the breathier tone I get from the Calicchio. I like to say it's a "real jazz machine".
The Xeno is much less forgiving when I push it. It's harder to get large tonal differentiation. It's probably because it's a heavier horn with thicker metal and the valve section was put together with jigs (which makes for a less vibrant horn overall). The Calicchio's valve section was simply wired together before soldering and therefore had less stress during construction allowing for more vibration in the final product.
The calicchio plays easier, has more of the sound I hear in my head, and feels better than most factory built horns I've found.
You should check some out if you're in the market! There are several bell and leadpipe options with endless combination options. Their bore sizes are M (.453), ML (.460), and L (.468).

Matt