Honestly, for all of these complications (never before did HMO/PPO plans combine coinsurance, deductibles, and copays into a single plan), the ratio of what you pay to what you get in terms of benefits has remained fairly static over the years (not counting premium hikes) That is to say, reconfiguring benefits to have ever more variables involved doesn't seem to be motivated by a desire for the insurance company to pay out less to an insured, at least not a heavy user of insurance like me. It honestly seems motivated by a desire to make the benefits as inaccessible and confusing to use as possible and scare away the casual users of insurance.
Now, I can't prove that's what they're doing, but seriously, I used to work in insurance for years, and now I'm in healthcare, and the way they're structuring plans now, at least at my employer (through a major US carrier) is frigging insane.
The 3 main mechanisms in insurance of sharing the "pain" with the insured and making him make smart choices about his utilization are copay, coinsurance, and deductible.
A copay is generally a fixed fee that the insured pays for any particular service. There's a copay for doctor visits, one for prescriptions (in the last 10 years, this has become a tiered fee depending on the cost of the drug), one for hospitalizations, etc.
Coinsurance means that you pay some percentage of each service. Traditionally, coinsurance is used for "out of network" coverage with doctors or facilities not contracted with your particular insurer and traditionally the split is 80%/20% so that the insured feels the burden of the expense and doesn't over-utilize non-contracted doctors.
Deductible means that you have some flat amount, sometimes very large, that you have to pay yourself before the insurance will pay anything. In the past, this has meant 100% coverage after deductible for contracted (in-network) providers.
What we have now, from Aetna, combines all three in one plan. We have a $3000 family deductible to meet before we receive any benefits, except for certain medications, which still have a copay, which evidently does not contribute to meeting our deductible when we pay it. We have a 10% coinsurance even on IN-NETWORK, CONTRACTED providers after meeting our deductible (this is capped at $5000, but still), and a 40% coinsurance on uncontracted doctors (double what it would have been in the 1990s, in other words). AND we have copays for all of our prescriptions that vary between $15 and $45 depending on how costly a drug is, and even then I've found there are some exceptions where the copay can go higher (and I have no idea how to explain that.)
For the average person trying to use their benefits, they just have to take the insurer's word that the plan is being administered properly. It's utterly ludicrous to combine all 3 cost control mechanisms into a single plan, doesn't actually save the insurance company much (if any) money, but probably looks good on some actuarial table somewhere and gives a couple of insurance executives an erection to think that they're using all possible methods to keep people from receiving "excessive" benefits.
It's complete insanity.