I used a Havana 3yo but.might try with a darker rum next time. I had it up in a nick and Nora glass but might switch to trying it on a large rock for a little more dilution

Upped the rum to 1.5 oz for a 6:3:2 ratio using Bacardi Maestro de Ron, Carpano Antica, and Campari to effectively make a white rum Valentino. White rum doesn't stand up to the red ingredients as well as gin does. Using a higher ratio of vermouth to Campari improves the Negroni when making it with Campari as the bitter red, though; I may try this with other Valentino/Negroni recipes.

Fine and clearly a rum negroni, when using Plantation 3 stars, Biostilla Ronda as the bitter (less bitter than Campari) and a fairly sweet Italian red vermouth. I did add 1 dash orange bitter.

Not sure if there was a recipe change but I definitely didn't feel like the rum was lost as other commenters suggested. Used Plantation 3 Stars and could taste it very clearly (especially around the middle of the flavour evolution), even though I used Punt e Mes instead of a less bitter vermouth. Will definitely make again. I do agree that it's better served down with orange bitters.

Mixed as written then switched to an Old Fashion glass on the rocks with Hinojos’ orange bitters suggestion. Tasty. The rum was still lost. I will back off the vermouth and Campari next time.

Liked this even better with Bacardi Carta Blanca, Cocchi Storico and Campari.

Found this quite tasty when made as written with Plantation 3 star, Cocchi Storico, and Luxardo Bitter Rosso. Added a couple ice cubes half way into it. As per Mr. Hinojos' suggestion, bitters complement this cocktail.

Went with Aperol instead of Campari, but this drink still needs served on the rocks.

This was not a very good cocktail in the proportions and serve suggested. Campari was too far forward and overwhelmed the rum. None of the depth or complexity you get with a classic gin-based Negroni or its bourbon-based cousin, Boulevardier. Would an aged rum would help? Will experiment... cheers!

Served over the rocks. This is a cocktail which does need to breathe and the rocks keeps it cool and opens up some of the more subtle flavours. Also tried with a dash of Orange Bitters - it did brighten the tastes. We outstanding with nuts and cheese.

I am a fan of negroni and campari. And I gave 2stars to this didn't enjoy the drink. Maybe the proportions are wrong. Used the same ingredients. Salud? from Mexico