Different nose cowl, and prop with extension. Personal preference only. I prefer the older model using the skull cap.

Tubular vs flat leg gear. Personal preference only. I prefer the flat gear.

Cleveland vs McCauley wheels and brakes. The older Cleveland

Circuit breakers vs fuses. Personal preference only. I have yet to replace a fuse in my nine years of ownership.

Simple flap switch vs flap preselect lever. Personal preference only. I prefer the older, more reliable, switch. Would have manual flaps if it were a option.

Larger vs smaller dorsal fin. Personal preferences only. I prefer the shorter tail.

Not one of the items above change the performance values of the 150. So value is based on personal preferences only. The 1968-1970 model would be my personal preference. So thus it would be of more value. Just because it is newer does not mean that it neccessarily is better.

So, you all may ask then why I am flying a long cowled, tube geared, steel wheeled, tall tailed 150??

I just could not turn down that newly overhauled O-320 in the nose for $22,000?? grin