We are renovating our apartment and choosing interior doors for the bedrooms and the home office. Our main requirement is good sound insulation so we don't hear what’s going on in the hallway and living room. From a practical standpoint, which option is better: hollow-core (flush) doors with honeycomb filling, or stile-and-rail (modular) constructions made of solid MDF or solid wood? Also, which types of perimeter door seals actually work effectively?