Having lived in Alaska for four years, I can say the cruises there are very popular and certainly a decent enough way to be introduced to the 49th state. However, if it were me, I'd probably rent my points and use the money I made to fly into Anchorage and use the city as my base to explore the state more fully than you can while on a cruise.
For example, fly into Anchorage and spend two or three days there to start. You can visit the natural history museum downtown, go hiking, rent a bike and ride the 120 miles of paved bike trails the city has, visit the Native Heritage Center, take in a show at the Performing Arts Center, fish along Ship Creek (which is downtown), golf at any one of a half dozen public courses in the area, visit Earthquake Park (along the Coastal Trail which is part of the aforementioned bike trail system), or any other numerous fun items to do. After those few days, drive down to Seward or Homer, about 3 hours and 5 hours, respectively, south of Anchorage. There are some great fishing excursions, superb hiking, wildlife cruises, and glacier viewing. Spend a couple of days there, too.
Then, drive to Denali Park--home to Denali (or as Outsiders call it, Mt McKinley)--for a couple of days. There are lodges, hotels, and inns there to stay. Again, there are numerous things to do, not the least of which is the possibility to see Denali up close (you can actually see it from Anchorage on a clear day). Wildlife is abundant as are tours that allow you to see said wildlife, though park entry does have some restrictions. You can even set up flight-seeing trips. Once you're done at Denali, plan to spend at least one more day in Anchorage in order to catch anything there you missed. Keep in mind that during the summer, you have lots and lots of daylight to help you do as many things in one day as humanly possible.
Great restaurants abound in Alaska, particularly in Anchorage, as do superb coffee houses and kiosks. The folks are friendly, helpful, and earnest in Alaska, and will do everything they can to help you enjoy your stay.
Okay, so I got a bit off topic. Yes, I think a cruise would be utterly delightful and worth the money you spend just for the scenery alone. Still, for a real treat, really go INTO Alaska. Have fun!