Here's my summary of the differences in the OSDE plans.
210 allows access to the entire Cartilla of providers but limits hospital access to basic facilities.
310 adds most of the best hospitals in the capital
410 and up add cosmetic surgery and cosmetic dentistry
I chose 310, and I was glad I had done so when my appendix ruptured some months back and I needed emergency surgery. My experience with the OSDE folks was incredible, and I received care so far beyond what would have happened in the US that I was shocked. There was even an OSDE care coordinator who visited me twice a day to confirm that everything was OK and intervene if I needed anything more.
The total cost to me was A$R 105 in take-home meds. House calls, ambulances, a night in the emergency room with a dedicated team of specialists, radiology including an MRI, my hospital stay in a private room far better than I've ever seen in the US (with a nurse dedicated to 4 such rooms), the surgery, triple IV antibiotics for several days - all were fully paid by OSDE.
The cost difference between 210 and 310 isn't great, but access to the Hospital Aleman, the Sanitorio de la Trinidad, and their equals adds real value.