There are many considerations you need to make if Act 60 is what you're referencing. To name a few considerations:
1. Cost of living in Puerto Rico is quite high. Expect to pay roughly double for the same foods you would anywhere else in the US, in terms of eating out OR the grocery store.
2. Applying for Tax Act 60 is a fairly lengthy process - depending on what service you go with, it can cost upwards of $20,000. This is just for the application, not for the other requirements it has such as becoming a "bona fide" resident.
3. This one is fairly minor, but worth noting. Puerto Rico moves at a difference pace than the rest of the US. Many online services we take for granted just don't really exist here. Schedule a doctor apt online? Buy car/medical insurance? Bank services? All of those either happen on the phone or in person. If you don't know spanish, this can be difficult to navigate.
I don't say this to dissuade you, just to recognize there are unexpected considerations to make that might not be immediately obvious/expected.