Along with two other families, my husband and our two kids (for a total of 12 guests) stayed at Casa Stella Rosa between Christmas and New Year's, and we couldn't have asked for a better house, locale, property manager, or overall experience.
The house is the real deal; everything is brand new and top-notch. High-end AC, lighting, security, and sound systems--along with amenities like the pool, outdoor areas, and daily maid service--make it feel like a stay in a luxury hotel.
Thanks to sweeping views of the ocean, the sunsets (always magnificent in CR) are simply unforgettable. We esp. loved the 3rd floor crows' nest for drinks/sunsets and late-night star-gazing.
Carla, the house manager, was INCREDIBLE--from our first moment of contact until she came to hug us goodbye the day we flew home. She arranged chefs, a catamaran, horseback riding, surfing lessons, in-house massages--and responded promptly to every single inquiry, including a last-minute request for a TV to watch bowl games. EVERY experience she booked exceeded expectations, esp. the catamaran and surfing lessons.
The beach access is direct, but note that you need to manage the tides and rockiness. Once you do, you're within minutes of Hotel Playa Negra (where we often went for smoothies, drinks, meals) and the surrounding beaches and surf. It's easy!
I could go on, but there is a character limit, so I'll just say everything about our experience was first-rate. Could not recommend Casa Stella Rosa more!