It (by which I mean, Parts A and B) definitely has its advantages to Medicare replacement plans (Part C). One of the downsides is....I think....no OOP max. Depending on the situation, that could get hairy.
It also has an unintuitive deductible structure for Part A, hospital services. It's not annual, but rather based on "hospital benefit periods," which I think basically translates to "per hospital stay." So you can have multiple deductibles per year.
That said, I've mentioned some of the very real, undesirable drawbacks to the replacement plans.
From what I've seen with our patients at the clinic I used to work for, and my grandmother, people with Medicare (A & B) + secondary coverage, often through a continuation of their job's insurance in retirement, but also there's independent plans you can sign up for, have the best of all worlds. They have their cake and eat it too, so to speak
*. The only tradeoff I'm aware of is you have to be able to afford the premiums for that situation. Many of our patients could not, and that's why we had so many people on Part C plans. They could afford the monthly costs (which are often $0), but they faced many unwanted challenges when it came to actually
accessing healthcare.
* I suppose Medicare + an HSA like
@MarqHusker talks about could be comparable, again, depending on the circumstances and health of the patient. I don't personally know anyone who had an HSA, and I wouldn't have been involved in that aspect of their billing/coverage anyway. Ergo, I'm not too familiar with the ups and downs of HSA's.