We stayed here for 4 nights in the 2 bedroom Wallauwa villa (2 adults and two kids aged 11 and 13). The setting itself is beautiful, perched above the beach looking out to the sea with nothing at all on the horizon. The hotel grounds are very nice, the pool is great, enough places to sit on chairs and beanbags in the gardens.
The villa itself is very good and generally clean. Two bedrooms, both with kingsize beds and two bathrooms, both with showers. A bit dim, even with all the lights on but that's a small point. Also has a large living area and kitchen (with random bits of crockery and equipment, but you're unlikely to be cooking), large outside table where breakfast is brought to you each morning. And large outdoor sitting area too.
What lets the place down is the food side of things. Breakfast is OK but not exceptional. You have to preorder the night before and tell them what time you want it. Then, in the morning, they bring most of what you asked for at a time of their choosing. If you asked for something at a specific time and told them you were heading out, then they brought it earlier than you wanted it (better than late though). If you gave them a time range, then they would normally bring it sometime after that window. Not a big thing but a bit annoying. Similarly, they don't always bring exactly what you wanted e.g. You want cornflakes and get muesli, you ask for egg hoppers and get nothing being told that the person who knows how to make egg hoppers is off that day!
Lunch was OK although nothing stellar and we didn't stay in for dinner. Tuktuk into Weligama was about LKR200 and approx LKR500 to Mirissa.
As for service, again, it was ok but with a little extra effort the hotel could really be great. E.g. Down by the pool, sometimes you got towels without asking and sometimes you had to really hunt around for someone to get you a mattress and/or towel. Again, not a big thing, just a bit annoying.
And what is it with Sri Lanka and sweeping leaves up the whole time, especially at 7am outside your guests' bedroom window? Please don't do it!
Overall though a lovely place and I would stay there again.