I am certainly no expert but after doing a bit of research, we are booked on the Diamond Princess on 09/04 out of Seattle. We wanted to leave on a Saturday so this limited our choice. Never been on a cruise before let alone to Alaska so I can't wait. I spend hours a day on the Net reseaching what to do. Celebrating our 30th.
There is a noticable difference in the bathroom between the two cabin types. The mini-suite will have a bathtub and more room in the bathroom in general, and large sink counter area. There is only a rather small shower in the regular double balcony or ocean view room. The mini-suite is a bit longer, giving you a seating area with a couch, also two TVs in the mini-suite, one for the bed area and one for the couch area. This refers only to the "in-line" mini-suites, such as those found onn Baja and Dolphin. I believe there are also some unique shaped suites in areas such as the rear of the ship and I know nothing of these.
The Diamond and Sapphire are supposedly the same, save for decorating I guess. By then the Diamond will have been in service a little longer and may have had time to work out the kinks. I scheduled to go on the Sapphire August 22 and am really looking forward to it.
I went on a Alaskan cruise with Princess last Aug./September (2003). Only 7 words can describe the experience. I WANT TO DO IT AGAIN! We did a cruisetour and started with 4 days on land. WOW this was by far the best cruise I've ever done and the next time I go I'm taking my parents (who by the way think Alaska seems boring and not for them) AND THEY WILL LOVE IT gosh darn it! My grandparents and one of my aunts who went with me did!
If you have the chance to do a cruise tour then DO IT! We started out in Fairbanks and worked our way south to the ship (the Dawn Princess). Here is a little tip for you: Take masquito repellent! The only time we had a prolem was in Fairbanks but it wasn't that bad ( I hear it's worse in July) but take it anyway even if you don't go to Fairbanks.