Investing in Spain: Good idea for non-residents(Americans)?

[Basit Siddiqi]

I lived in Madrid, Spain for about 8 months and I am curious if it is possible for non-residents to successfully have rental properties within the country.
My concern is mostly from a tax standpoint and whether it makes sense.

My research shows that 
Non-residents of Spain(but a resident of Europe) pay a flat rate of 19% on NET RENTAL INCOME.
Non-residents of Spain(Not a resident of Europe, such as the USA) pay a flat rate of 24% on GROSS RENTAL INCOME.

The difference of paying tax on Net and Gross is huge.

Americans are not able to deduct expenses such as mortgage interest, taxes, insurance, cleaning, repairs, etc

A pro that I can think about when it comes to invest in Spain is that overall costs are less - Mortgage rates are currently around 4% - 4.5% while it is around 6.5% - 7% in the US.

Am I reading the tax law correctly?

Are there americans who are making the numbers work?
I would love to hear from others who are making it work and what the numbers are like.