I have a number of Colnagos. There is a slight evolution of the geometry over the decades, but all share a common theme.
For their lot they are a bit sharper handling, they request attention and deliver entertaining handling.
I think they are best at rides under two hours, not my first choice for an all day last two hours finding one very tired ride.
Not a classic 70's criterium bike, the bottom bracket is too low, they do have in general short front center dimensions, the mix of head angle and fork rake makes the steering rewarding but I think requires attention more than say a Masi of the same year.
The Mexico model one feels a bit "loose", I will attribute that to the light tubing.
In my size range, they are otherwise probably all SL or equal to SL, I place SLX essentials the same, only advantage is a stiffer tube to mount the front derailleur braze on to.

Gios went shorter on the top tube for a given size but added a bit of fork rake at least in my sizes.
My Grandis is my "poor man's" Colnago, very similar.