Powerglide Transmission Question

[72step]

I currently have a nova posi rearend converted to work on our trucks for sale and a guy is offering me an aluminum powerglide tranny on trade. It is the long tailshaft model. Last year I sold a short tailshaft model powerglide tranny builder and that guy said the short tailshaft is what is more desireable at least for him it was. Is the long tailshaft powerglide less desireable or what is the difference? Thanks...