If you tend to get seasick, cabin location is really important. It is a question of engineering, really. The lower and more central you are in a ship, the less roll and sway you will feel. Even if you choose a balconied stateroom, choose the lowest level and the most midship one you can find. The higher decks and cabins at the very front (forward) or back (aft) of the ship will rock and roll the most.
A concierge can take care of all those annoying practical matters you need to tend to on a cruise: making dinner and spa reservations, booking shore excursions, making requests of the front desk. Their services are included in the price of many suites, and on some ships the concierge has a desk in an exclusive concierge lounge where suite guests and high-level past passengers can snack, drink and relax in private. Concierge-level cabins may also come with in-cabins amenities including welcome drinks, fruit baskets or afternoon canapes.
In this age of mega-ships, cabins now come in all shapes and sizes. In addition to the typical boxy inside and outside cabins, you can find expansive suites, duplexes and lofts. Balconies also range in size from small affairs barely able to squeeze in two chairs and a drinks table to huge wraparound decks with outdoor dining tables and hot tubs.
For some reason, most cruise lines assign their nicest and most expensive cabins to the highest decks, usually just below the pool deck (most likely because if you have a window or balcony, you have a more sweeping vista). Still, it is the pool deck that often causes the most noise problems, so if you do not want to hear scraping chairs at the crack of dawn or yee-hawing pool parties until the wee hours, go down a level. In fact, when it comes to noise, the best bet is to select a cabin that is both above and below other cabins.