First visit to Buenos Aires

If you want to actually experience BA then don't stay in 4 or 5 star hotels in Recoleta or Palmero. Try a boutique hotel in La Boca or a business hotel near the train station.

Por ejemplo,

https://ippa-hoteles.com/filiberto-by-ippa.html

https://www.savoyhotel.com.ar/es/gallery?

French and Italian cuisine is indeed terrific, especially the gelato!

Be aware that they do not generally eat spicy dishes -- they think Mexican cuisine is exotic.

I think the black market for currency is no more, you should be able to use credit cards.

Great city, but there are some areas of the city you absolutely do not want to go into. Check with the locals first.
No need for expensive hotels, we stayed in a B&B.

I believe that the two top luxury hotels in the city are PALACIO DUHAU and the FOUR SEASONS.
(I've been researching this myself for near future). Neither is in Palermo, however.

The "crisp new US bills" relates to exchanging them for Argentinian pesos (and actually this applies everywhere, since I do this whenever I travel).
ATMS in Argentina also only allow limited withdrawal amounts and can have hefty fees. There are situations and places where you will want to have at least some cash currency. The class of hotel you want may have an exchange available? But I learned they don't always have it on hand!
It's a beautiful city. I suggest an architectural tour. Mine was a half- day as part of the group tour I was on but it so enhanced the experience and we were shown details I would have missed on my own.

We spent a month in Buenos Aires in February/March 2025. We stayed in Airbnb's, most of the time in Recoleta, but the last week in Palermo Hollywood.

If I was going again, and staying in a hotel, I would probably stay at Blank Hotel Recoleta. We had friends who stayed here and recommended it. It was around the block from our AirBnb on Avenida Callao. For me, this area had more of a neighborhood feel than the hotel zone further north by the cemetery. But, depending on what you are looking for, the area east of the cemetery could work. It had more of an upscale tourist oriented scene than what I was looking for.

Palermo Hollywood was great, a more relaxed vibe than Recoleta, but I'd probably choose Recoleta again since it is closer to other BA sights we were interested in visiting (the cemetery, Teatro Colon, Fine Arts Museum, La Boca, San Telmo, etc.).

The cash situation was rough when we were there. The Blue Rate (the unofficial/underground rate) was significantly higher than the official rate you get at banks or ATMs (and ATMs were often out of cash). We ended up using Western Union to wire ourselves money, which had a conversion rate close to the Blue Rate. Our experience was about 80% of restaurants we wanted to go to accepted credit cards and we used cash for the other ones. Some of the restaurants that were cash only would accept US dollars and return the change in pesos, some would only accept pesos.

If I was going for 3 nights, I would probably bring some crisp new $100 bills in case, but try to use my credit card for everything.

We went there as part of a Tauck tour and stayed at the Alvear Palace Hotel. Great hotel, close to the Recoleta.

Happy travels!