Hi there
my sister and I stayed in Tria Adelphia in June this year and they were really great. They have a good size pool which was always kept spotlessly clean, and they're happy for children to use all the usual lilos etc in there. They also have a small bar / restaurant. We only ate there once at night and once at lunchtime (only because there are so many nice places to try) and the food was home cooked and delicious. We found the bar was a good place to have the first and last drink of the night although plenty of people stayed there for food and drink all evening. The Tria Adelphia is run by a lovely couple called Philip and Eleni (apologies for incorrect spelling of their names....) who made us really welcome. They're currently building a new block of apartments (making three in total) which i think are due to open next summer. And it's about a 15 min stroll to the village and beach. That's about it. We had a wonderful time, loved Arillas (it was our first visit although we've been all over Greece many times before) and we're hoping to get back to Arillas and Tria Adelphia next year. I'm sure you'll love it.
Hope this helps
Sue C.