This is not an HSA. It's an FSA (flexible spending account). I would not recommend anyone use an FSA. Obviously, the biggest drawback is that if you don't use your contributions within the year, they are gone. With an HSA, the money is yours forever. And it's inheritable, so even if you die, it's not absorbed by your health plan. An HSA is kind of like a retirement account in that you can use it for anything you want without penalty after 65. Before 65, you can only withdraw from it for health care (which is actually pretty broadly defined) or suffer a penalty fee.
Generally, the premiums are less than what most people are paying for their standard insurance plans. You can look into it to find out, but you can get coverage for about $50/month and up, depending on your deductible and coverage. Mine is $47.36. You don't have to contribute to the HSA at all. But it would understandably be wise to at least get it up to the amount of the deductible, which I think is by law is $5100 max, but can also be less. I would actually like to have a higher deductible since it makes the insurance cheaper and I rarely go to the doctor and would rather pay out of pocket for most things. Health insurance is not for every random prescription or visit, it's just for getting hit by a bus or something that no one can reasonably be expected to afford. The reason most people pay so much for insurance is because they are over insured. Your HSA can cover the small stuff. Your insurance picks up the really expensive stuff.
This is a drawback of HSAs. You are limited to a fixed maximum contribution per year, so it can take some time to accumulate a sizable HSA. Although wise investing can make your HSA grow faster. Also, this is less of a problem for young people who are unlikely to experience significant health problems before they can build up their HSA. Although I would not say that HSAs are only for the young and healthy. I think they have something to offer for others as well...control of health care, tax free retirement savings, ability to invest, independence, and it puts the responsibility of personal health on the patient, where it should be. One thing you could do would be to start out with a lower deductible if it makes you feel more comfortable, then raise the deductible as the HSA grows to save money on premiums. Here are some sites that answer some questions:
US treasury department
Kiplinger FAQ