Well, picking a cruise is always a mixture between: destinations, length, mixture between Seadays and poets, cruiseline and of course rates.
We always like to go with Celebrity and we do like smaller ships. This cruise had China and Japan, both were on our bucket list plus South Korea which was an addon (and a pretty nice surprise).
Millennium is an older ship, however we red before in other reviews that it is well maintained and we can confirm.
Everything fine, balcony is a little bit small, but sufficient. Cabin is at the very end of the corridor, so quiet but a little bit longer ways to stairs/elevator. No notices from above or below.
Easy to visit on your own, good metro system, center of city easy to walk through
There is not so much to ein Kobe itself, you can easily walk through the city and you should for sure have some Kobe Beef. From Kobe you can do excursions by train to Osaka or to Kyoto. Train System is very efficient in Japan, and it is pretty easy to find your way and to buy tickets at the ticket machine. There is always somewhere a plan in English, look for the station number where you want to go to, enter the number in the machine (after selecting English as language) pay by cash and get your ticket. You have to enter the ticket to get to the platform (signs are in English as well and Japanese people are very friendly and helpful) and you have to enter the ticket again to leave the platform at your destination. If you made a mistake and got a wrong ticket, the gate will ask you to pay additional money, there are machines where you can pay the difference. Sound much more complicated as it is. Just remember which station you started, so you’ll find your way back.
As at all ports in Japan everything very well organized by Japanese tourist boards. There are always shuttles into town, helpful people to assist, money exchanges. Free WiFi, etc. etc.
We staid in Yokohama as we staid in Japan after the cruise and had time for Tokio later, other took the train to Tokio, which is a short distance by train.