Insurance company "administrative overhead" is capped at 15% of premium dollars; before Obamacare, it was typically over 30%. That money is non-productive. (By comparison, the VA's administrative overhead is astoundingly low, at 2%, and a recent study showed the VA and private US hospitals getting comparable outcomes for three major medical problems. I.e., the VA got equivalent outcomes at much lower overhead cost. Just saying.)
People with pre-existing conditions are no longer excluded from insurance. Sometimes retroactively, long after an insurance company has agreed to insure them and has been using their money.
Insurance premium annual increases before Obamacare were quite a bit faster than under Obamacare.
The most valuable benefit from having insurance - even if you have an effectively infinite deductible! - is that you pay rates the insurance company negotiated with the healthcare providers and pharmaceutical companies, not the list prices you'd pay otherwise. The difference between these can be enormous.