I had a cento 1 back in the day, then sold it and bought a cento 1 superleggera. Those two bikes to me were pretty different. The cento 1 was the impetus that is my bike craze today. Silly smooth, good (not amazing) handling, predictable. The sl was a lot livelier and harsher in my opinion. Although the geometry was the same, it really felt like a different ride.
The zero I bought as an experiment with lightweight parts. Epic fail! Although the frame was strong enough to support my growing waistline, the lightweight parts were not. That said, by the end the build was gen II ventoux, ax lightness seatpost, extralite stem, mcfk bar, and campy ti group. 12lbs or so. Not sure if it was because of the lightweight parts or the geometry, but I felt the bike was twitchy in its handling. It really required attention, much more so than my other superbikes (6 other bikes). The ride quality was nice, a muted very even feeling ride. Close to the cento1 with a slightly snappier feel. Also, I broke an AX lightness Morpheus crankset, the Orion brakes I had on it were squishy, I never got the powercordz to work right, and the ventoux would flex when sprinting. So though the ride was nice, all the other factors weighed heavily on my decision to sell it. Yes I could have swapped out parts and all that. But unfortunately, I'm a design snob, and decided at the end of the day that I didn't like the curved fork, the external cable routing and most of all the 386 graphics. I didnt love the 31.6 post, but could live with that. Then why did I buy it you may ask? Remember, the start of the project was around lightweight. I already liked wilier from the cento, and the 750g was appealing. But, of course I got the fattest one which was 808g and a 330g fork after being cut.
Furthermore, Berk was selling a Cento SR for a nice price at the time so I bought it. After building that, it provided 80 percent of the feel of the zero, felt more solid and stable, and I preferred the graphics. It rides somewhere between the cento 1 and sl. Not as plush as the cento 1 but not nearly as harsh as the sl. And to boot it tracks and handles better, has ISP, a straight fork and interesting graphics. It's a winner in my book.