Just returned from a 10 night cruise of Eastern Med on the Equinox. Would definitely recommend it. The ship is very big but you never feel crowded, we had 3 adults (son is 16) in our cabin and it was fine - the extra bed was a converted sofa but long enough for him (6ft) which is unusual. We had a deluxe ocean view cabin which comes with a balcony - wonderful for when you are arriving or departing a port or catching the last of the afternoon sun. The shower is a good quality, toiletries are topped up every day and everything is immaculate - cabin is cleaned twice daily with the usual cruise touches - chocolate on your pillow etc at night. Our son was really impressed with the flat-screen TV - about 20 free to view English films and you can view your account, photos etc through the same medium.

The staff are very attentive - how they remember your name after the first day is very impressive - they seem to be a very happy bunch.

Food was exquisite - we could not do justice to the volumes but everything was perfectly cooked. We ate in the main Silhouette restaurant on all but one evening - only 2 formal nights when men need to wear a suit/tuxedo but other than that was smart casual. If you do not want the fuss of that, it was more casual in the Oceanview "cafe" on the 14th deck - do not be fooled by the word cafe - it was better than most 4 star hotels we have stayed in. We only tried one of the speciality restaurants (Silk Harvest) which was excellent - just seemed daft to pay the surcharge ($25 - 35pp) when the main restaurant was so good. Did hear good reports of the others though - particularly the Murano.
Drink - we pre-purchased a soft drink package for our son but the rest we paid for on board - very expensive but good quality. The minimum we paid for a bottle of wine was $30 (about £20 - would have cost £10/12 for the equivalent in a restaurant at home). Cocktails are about $7.50 each but they seem to have a happy hour each day (at different bars around the ship) when they are just $5. Tea/coffee and cordial type juices are free - you just need to go the 14th deck to collect.
The shops were also very expensive - aimed at a designer market.
Loads of opportunities for formal photos - up to $20 each for 10x8 but they were very good.
Trips - we went on 5 organised trips, again not cheap but each one had an excellent tour guide. On a couple of other days we took the shuttle ($10 pp) to the local town. Everything was very slick.
Entertainment - 3 formal shows - were all ok but the Cirque de Soleil type show on the last formal night was particularly good. Casino was very popular. Loads of bars each with live music - so something to suit most tastes.
Pool - the main area got very crowded with young families but we always managed to get a sunbed on one of the decks. Towels are provided. Indoor pool was lovely - adults only. Did not get to try the Spa - ran out of time and it looked expensive.
Other guests - mainly American.
If you get the chance - go!