I have about 300 hours in Stinson 108's in the last year and a half. My buddy flies a 170B. We argue about the better plane all the time. He has the 300A in his 170B and without a doubt I am off the ground much much quicker than he is. Single pilot light in gas I get off in under 200' (Video:
https://youtu.be/kmQ-ieGmcUY ) He is upwards of 300 - 500 depending on the day. Landing is a different situation. We are real close on landing much of it probably coming down the the bravado of the pilot that day. Truth be told he had the Horton STOL kit on his and with the extra wing area I think the 170B is shorter (Don't tell him that, I'll deny it till the day I die) My Stinson 108-2 has VG's for help and it get down and stopped around 200'. (Video of landing:
https://youtu.be/DdItK_AbZnl ) Either way both planes do well for our needs. In cruise the 170B is a bit faster but again it depends on the day the only true advantage I'd say the 170B has is it's lower fuel burn. I prefer the tube and rag construction of the Stinson it's more rugged and the fabric is easily repaired compared to a semi monocoque design. I also like the smmoooth running Franklin 165. The 170B has a bit more back seat room for folks but the removable rear seats in the Stinson 108 is great for camping it gives you so much room back there for storage. The Stinson 108 has more useful load. I am super fond of the Stinson 108's classic look and find it to be one of the best looking planes out there, on the ramp people seem to agree folks consistently walk by the C170 and right up to the 108 and start asking questions. On flight characteristics without a doubt the 108-3 is one of the best flying aircraft in cruise I have ever flown (a video I made about flying the 108-3:
https://youtu.be/qd_BCZxcAGQ ) though it's ground handling characteristics caused me to sell the 108-3 and purchase a 108-2. The 108-2 does not cruise as straight and stable as the 108-3 as it requires much more rudder input to stay straight but on the ground it is a very easy to fly tailwheel, maybe the easiest I have flown besides the Pawnee. The 108-2 and C170B are comparable in cruise and ground handling as far as landing the 170B has a bit heavier tail and it seems to be a little more of a challenge in a crosswind but both are docile. Overall they are similar they fly together well. I prefer my 108 and he prefers the 170. Questions I'd ask, Do you want a tube and rag or a semi monocoque design? Am I willing to learn how to maintain a Franklin engine as it is different than a lyco. or Cont. maybe teach a mechanic the differences? The results will be the smoothest running engine you have even been behind. Both are great aircraft if you are looking for a light touring backcountry bird.