I'm finding out most of those plans are network deals.
Certain docs, hospitals, etc.
Bingo!
All "so called" Medicare advantage plans are just PPO,HMO insurance companies paid $1,200 and upwards per month, to absolve the Medicare system from further costs.
Do your research on the subject before you go to the cheapest option.
Once you step into that trap of "free" you will end up having to go to only the medical facility available in the network.
When you go down that path and move to an area not covered and want to go back to standard Medicare, pre existing conditions will drastically increase your payments to Medicare.
By just paying for a supplemental policy of about $290 a month my wife and I can be covered all through the US.
Dental care and eye glasses our the least of our worries.