I would suggest you post this on the Alaska forum. The number one answer you will get will be, base it on what you want to see. The number two will probably be to do the land part yourself, it takes longer to travel across the land then a cruisetour will allow.
That said, I took a HALcrusietour last August and had a blast. I initially was looking at Princess but the one place my wife wanted to go Princess didn't (at least the TA told us that) , which was to Dawson City in the Yukon. So that is how we based our decision,,based on something we wanted to see. The other thing we wanted was to see Denali and HAL did give us the 7 (which actuallly truned out to be 8) hour Tundra Wilderness tour.
As someone will point out to you, the land part can be a lot of driving,,and it is,,but I liked being driven around in a really luxurious bus. I normally drive so it was easier for me looking out of the giant windows,,but the days are long. Really.