Tatsiana,
You have to take the news on "getting harder" with short-term rentals with a large dash of salt - the Spanish have a very established history of operating in "grey" areas (or black, for that matter - official estimates peg roughly 30% of GDP to be in "black" money right now), and especially when it comes to vacation rentals, so any governmental moves towards regulating these would be seen as an imposition. Regulations vary from region to region, and it's true that in markets like Barcelona they've clamped down hard - Madrid has pushed back against Barcelona, though, and recently vetoed a significant fine that Barcelona tried to issue against Airbnb (corporate). In Andalucia, however, the regulations are established only since last year, and all in all, they're fairly easy to work with; there's hoops to jump through and rules to follow, of course, but all in all we don't see it as anything unreasonable.
As far as being a good market for investing in vacation rentals, it can be a fantastic one! The country has experienced record levels of tourism the past two years running, with annual visitors exceeding 76 million people (the population of Spain is around 40 million). Property prices are still depressed from the market crash that saw up to 40% decreases in value, but have been on a very slow, but steady, uptick for the past two years as well. In other words, it's a great time to buy in Spain right now if one wants to get into vacation rentals, as two months of peak pricing can pay for the whole year of PITI (especially with mortgage rates under 3%). Like @David Fernandez said, though, purchase costs are significantly higher than US real estate, so your CoC returns might be shy, but your overall ROI can be substantial. I'd say to shoot for coastal areas - these are recovering value the fastest (besides Barcelona and Madrid metro areas).
We're investing in the Malaga area, and here you've every kind of option by choosing different towns - Torremolinos, Benalmadena, Fuengirola, Mijas / Calahonda, and Marbella tend to be the popular spots, but there's myriad other smaller towns around that have their own draws. Our picks tend to be in the Torremolinos, Benalmadena, and Fuengirola areas though, as these are connected by easy train to the Malaga airport (and Malaga city center). Overall we've been happy with business here; it has its challenges, without a doubt, but the quality of life we can have while we build our business (instead of when we've made it, so to speak), is something we value highly.