Sunroom or addition?

I am thinking about adding more space to my house.
Ideally I would want a 15x10 or 15x15 area where I could have a dining nook or some open space maybe with kids indoor play area.
I could do this via a regular addition without changing the roof dramatically. I’ve been given ballpark quotes 30k to 35k to do this with permits. A regular addition will add to the sq footage of the house ( and also increase my property tax ).
The other option is to have a sunroom installed. The sunroom from what I’ve seen will be a bit bigger - maybe closer to 275 or 300 sq ft and cost seems to be 40k? These are numbers I am seeing online and dont have quotes yet. Will a sunroom add to the sq footage of the house ? What does it do to the house value?
The big downside with sunroom seems to be insulation problems and sometimes water leaks. Other complaints have to do with how it does not blend into the house like a normal addition would.
What have your experiences been like?

Out of curiosity, what exactly is the difference between a permitted sunroom and permitted addition aside from the amount of windows?

I guess I’d always assumed sunrooms were a way of getting enclosed livable space without having to either pull permits or do things that an increase in square footage or bedrooms might require (like adding a parking space or a garage space or paying a fine).