Haven't been on the Constellation- but I have been on other Celebrity ships. The alternative casual dining is excellent. This is where Celebrity trains their waiters so service is excellent (the wait staff wants to be promoted to the main dining room). It is not the same menu as the main dining room - the food is very good. Since it is a smaller venue, the food is more cooked to order. There is an additional charge of $2 per person (that covers the tip), but we had such excellent service we tipped extra.
Millennium-Transatlantic-9/01, 10/03, 11/05
Zenith-Special Caribbean 11/06
Back to back Millennium 28 days - Mediterranean 11/18/07, Transatlantic - 12/2/07