I have done the Alaska highway route and I have done the other route via Kitwanga. The Alaska highway has been upgraded a whole lot over the last few years - it is getting very smooth these days. They have straightened out the highway from a very narrow, crude and rough road to one that is quite navigable. There is road construction in some places but overall, the road is quite good and it is paved all the way. I like the other route via highway 16, but it is still quite narrow, rough in places, and very remote. Beautiful scenery, though - another drawback is the gas prices are quite atrocious. The remoteness and the cost of gasoline or any car problems make it a little risky. You want to make sure your car is in good condition. About the car rental - can''t help you there because we drove our own vehicle both times.