Essenza di Colonia is indeed an obvious Colonia flanker, however I feel that this fragrance is a lot richer and more masculine than its predecessor. I had considered wearing the original Colonia myself in the past, yet with Essenza di Colonia I wouldn't dare.
The scent opens with highly concentrated lemon top notes and zesty hints of orange blossom. It's essentially the scent of a classic cologne; citrusy and fresh. The sweetness apparent in the original is not present in this fragrance, nor are the floral accords. Earthy and grounded herbaceous notes are what makes up most of the heart.
For the first few hours, Essenza di Colonia struck me as being a rather intensified citrus cologne. It refused to be shy, adopting instead a rather biting and rough quality. I find it very intriguing to say the least. I particularly like how it can smell classy one minute, and fierce and rude the next.
The drydown does tend to develop into something soapy and clean, however the masculine qualities remain. Essenza di Colonia is quite a strict, 'no messing around' kind of fragrance, that exudes a lot of distinction and sophistication. The sillage can be strong at times, but it's mostly inoffensive, while the longevity is very powerful, especially on clothes.
While it does appear to be a warm weather scent, I think it could also work well in moderately cool weather, like those in-between seasons before the heat sets in. All in all, I'm impressed.