I used the JR Hokkaido Rail Pass to travel from Hakodate to Onuma Park, Sapporo; from Sapporo to Otaru, Asahikawa, Biei and then to the airport. The pass can also be used for JR Hokkaido buses that go around Sapporo. The voucher was sent via email, when I arrived in Japan, I went to Hakodate station to exchange the pass. The staff at the station were very enthusiastic and attentive.
The pass is a bit fragile so you have to keep it carefully. Only those who travel a lot should buy the pass. The quality of Japanese trains is unquestionable. The trains are always on time, the outside looks a bit old but the inside is very clean, the seats are spacious. Some trains require reserved seats such as Hokuto and Lilac, the more you learn, the smoother the trip will be.