How does Canados 86 compare ...

I've only been on a couple of Canados, I have to say the quality of the interiors are fabulous, much better than that of some other Italian marques.

From an engineering or seakeeping angle, I couldn't tell you.

There is a big difference from a Canados, to more full production orientated builders in the EU as Ferretti, Azimut, Sunseeker, Princess etc etc.
They are usually also a more heavy in same length to the boats above, and also had a bit of higher premium on new purchase.

The main difference from a Canados to the more production builders is that Canados built to order, and spec'd and customized as the first owner desires.
That means that the interior (sometimes even the exterior) is always different to the next hull.
It is not easy to find a Canados the same to the other, although sometimes it happens.

I would compare more a Canados from Ostia, Rome (Cantieri Navali di Ostia) to some of the other Viareggio builders as Falcon, Fipa Maiora, Sanlorenzo, Amer, Tecnomar, and Posillipo Technema series from Rome. To give a few names of my head.

The 86 has a good hull (quite flattish V aft) , and has been a best seller for the Rome builder.
It is also a boat which a captain told me runs well even with the smaller 1600hp engines some of the models have.

As is with all boats, but more so with larger boats, routine maintenance may play a key role in all how a boat turns out to be.