We did a cruise tour once. I did not like the waiting around and we seemed rushed.
My in-laws enjoy bus trip vacations and have done a cruise tour twice.
A couple examples of what I didn't like.
If we stopped for a bathroom break you are waiting for 50-60 people and before our group was done another bus had came to add to the crowd.
When we went to Denali we went on the wilderness explorer trip. We had just a few minutes for a bathroom break before we had to leave on the explorer bus. Same situation when we came back from the trip. We did not even get a souvenir from Denali not enough time.
The nice thing was no driving, hotel rooms planned for you. No worries.
I defiantly recommend spending more time in Alaska before or after cruise but personally I would rent a car and go at my own pace.