The trip was actually a bit over 14 days total but the other 4+ were spent going to/from Hokkaido on the various trains - NRT-Sendai-Aomori-Hakodate and Kushiro-Morioka-Tokyo-NRT with a few short stops along the way. The 10 days I mentioned were actually all on Hokkaido - 2 days Hakodate, 1-1/2 days Sapporo, 2 days Asahikawa/Asahidake, 2-1/2 days Abashiri + Shiretoko, 2 days Obihiro/Kushiro. I used up my 14-day Rail Pass getting back to Tokyo and had to pay cash for the last train of the trip, back out to NRT for the trip home.

Yes, I was on the move a lot. I did get enough images for a small book and a newspaper travel article but would have done better with more time. I was almost 64 at the time and will admit that I pretty much collapsed and slept the entire way home. Thank heaven for business class, lie-flat seats.

For a shorter stay, I think I mostly agree with you. Hakodate is worth at least a couple of days, with the westerner influenced neighborhoods and churches, morning market, rope-way for evening mountaintop views of the harbor and the northern peoples museum. It rained while I was in Sapporo but I still enjoyed the botanical garden and downtown area. Some more time there would have been useful. I feel that any visitor should get up into at least one of the national parks for the mountain experience. There are several to choose from that are closer to Sapporo than where I concentrated. Since I was primarily there for fall foliage photography I made my choices accordingly. Different times of year would suggest other areas. I am sorry I missed the lavender fields and other farming regions but they were mostly muddy messes when I was there.