It's a complex package, I'm not familiar with the specifics, but I know it does more than "simply takes the current system and mandates that everyone participate in it."
Well, to pick one of my many pet peeves with the legislation, they imposed excise taxes on medical devices, which covers everything from pacemakers to hearing aids to contact lenses. How exactly are new taxes on medical products going to bring down costs? Why should a pacemaker be taxed at all? It's not exactly a luxury item.
And the mandate could lower healthcare costs as well. People skipping out on their bill, not getting preventative care, or having to deal with collections agencies, these are things which could be reduced or eliminated with the mandate.
Except they won't be. For starters, the legislation specifically denies the IRS any enforcement power whatsoever. You can simply refuse to pay the penalty and the most they can do is send you a strongly worded letter. They can't put liens on your property, haul you into court, audit you, or use any of the other enforcement mechanisms at their disposal. More to the point, it's cheaper to pay the penalty than it is to carry health insurance. With guaranteed issue why bother having insurance at all, until you need it? An analogy here would be if you had the ability to buy flood insurance as the upstream levee failed, or the ability to purchase homeowners insurance after the house caught on fire.
Notwithstanding all of the above, the costs imposed on the medical system by deadbeats are vastly overstated, and even at that the mandate won't do much to address them. Deadbeats play a small part in the inflation of healthcare costs, bigger issues not addressed by the ACA include the ever increasing cost of malpractice insurance, an overly burdensome regulatory system, a broken patent system, a shortage of primary care providers, and the incomprehensible nightmare that is medical billing. The latter is something that nobody outside of the industry ever talks about, as a overly simple analogy, imagine the PITA it would be to go through your car insurance carrier to pay for oil changes and wiper blades.
This is one of the best articles I've ever read about our healthcare system. It does not push a left or right wing agenda. It outlines issues with the system that both the Republicans and Democrats refuse to talk about. Give it a read, I'd be interested to hear your thoughts about it.