As a specialty coffee apologist one of the most challenging yet most important parts of recruiting new brethren is convincing people that coffee is more than a solvent for cream and sugar. If you’re reading this, chances are you’ve cringed once or twice watching a fine cup of coffee desecrated by “extra cream” or “extra sugar”. To clear the air sooner rather than later, there won’t be any follow up article by this author defending adding any sweetener to coffee. Coaxing out and appreciating the natural sweet notes inherent in well roasted coffee is one of the pleasures of specialty brewing. Modern diets are drowning in added sugars anyway; I just don’t see any place for this. As an aside, if you’re faced with a lousy brew and just need to make it drinkable, try a pinch of salt instead.
Alright, so when is a bit of cream/milk a benefit to specialty coffee? That’s ultimately for you to decide, but consider adding your cream in a metered fashion for the purposes of either weaning down how much you’re using or discovering just how little is really needed to change the body of the cup without washing out flavor notes. First, I would be weary of using any in more floral or acidic brews. It’s likely to curdle and those notes typically get best emphasized with less body, not more. I never add anything without tasting a brew as is first. Most of the time, I add nothing, but I don’t hesitate with cream for a medium or darker roast if I feel like I’ve missed the mark a bit on the body of the cup. I use whole milk, but choose whatever you prefer, just avoid things with flavor or sweeteners already added in. The key is adding very small amounts and doing it in reproducible way. If you already use milk and want to try backing down a bit, start at 5-10 mL and slowly wean your way down to 1-3mL per cup. You’ll notice some change in the body of the brew with as little as 1mL added, and you will not mask the flavor profile of the coffee with this small amount of milk added. I have tried doing this with a dropper, but the milk doesn’t last long in a dropper bottle, so I tried using a wine thief I had. Dipping this directly into the milk jug worked well, but it was far too large. I’ve switched to using a long glass pipette, and it’s worked very well for small amounts. I use it just like a wine thief (finger over the end of the glass pipet to siphon out a bit of milk directly from the carton). It is fragile, so be careful, but I’ve grown comfortable also using this as a stirring stick to mix the milk in after depositing it into the coffee. A hot water rinse out typically does the trick for the glass pipette and soapy water every once in a while keeps it pristine. You’ll need to find a good way to store it; I’ve been placing mine in a universal knife holder that consists of thousands of plastic strands that deform when you slide something in instead of conventional knife slots. Next time you have a jammy or chocolatey brew that tastes like it could use a bit more body, try playing with very small metered amounts of milk added in. It might be just the thing to salvage what might otherwise have been a mediocre cup.
Edit: TLDR - - consider adding a very small amount (1-5ml) of milk if your brew seems to lack body. If you use large amounts of milk/cream and are interested for health reasons or to better taste the flavor profiles of the beans you brew, using a precise measured wean can help tone down the amount you are using.

Cream is a very American thing, so I'm a little confused what this article is saying, as sometimes it mentions cream and milk. How interchangeable are they?
Honestly, I wonder if this is at the core of at least some of the underlying snobbery. I've seen the things Americans put in coffee and they're not right.
Over in the real world coffee is flavoring for milk. I said it, and I'm correct.
I'm Australian. We do coffee snobbery better than the Italians. And we only use milk when it's not black, never cream
Where I live in the US, it’s really not too important, as long as some kind of dairy goes in. There’s usually a choice of 2%, whole, and half-and-half. Actual cream is rare. Nondairy creamer is usually set out in little sealed cups at restaurants because it doesn’t need a fridge. Broadly speaking “milk” and “cream” are interchangeable terms for regular dairy, and the person ordering/drinking will need to ask if their specific preference is available.
Heavy cream in your coffee is an indulgence worth experiencing. It really coats your mouth with the fatty cream, so it's not something I would want to do more than occasionally. It's really good on the rare occasion that I bought heavy cream for something else and want to use a bit more of it before it goes bad.
Heavy cream (whipping cream, 36%+ milk fat) is probably not good daily, but it is great in coffee, it can even make Folgers palatable.
Cream as in milk products of any sort. Everyone has a different preference. I like whole milk, hence the specific reference, but cream or half and half or lighter milks work as well. Full on cream or half and half require even smaller volumes. Half a mL of half and half can be effective even.
Someone says “cream” it could mean powdered creamer, half & half, or the 2 inch list of ingredients liquid garbage that is international delights flavorings.
Milk is adjacent to this category, but unless it’s whole, will add an “off” milk flavor to the coffee which is pretty foul. Skim, for example, will destroy any cup of coffee with an unmistakeable pure milk flavor, no natural sweetness of cream, and no creaminess to the texture.
Pure cream is almost oily in the coffee.
“Cream” is more or less just half and half. Creamy milk, slightly sweet such that the bitter edge is cut. True half and half has 2 ingredients: milk & cream.
Sweetness is the last thing I want in coffee! Being Australian, I'm quite familiar with milk. That's what our entire cafe culture is centred around