Hi Mathsboffin,
Havent stayed at kaloudis so cant comment on noise from there,
Tria Adelphia is about a 10-15 min walk to resort centre, its lovely and peaceful, yes older couples do go there.
Mathraki is about 5 mins from beach. Its near enough to tavernas etc but you dont get any noise at night. Lovely clean rooms, fantastic family, look on reviews on here. ou would probably be better suited here with teenage boys.
Hope this helps.
You will adore Arillas.
Sharon x