Differences with Back to the Future at DVDSoon.com
 

Why are there 2 different versions, aside from the P&S vs WS??

That's a very good question.

Usually when this place has 2 different versions listed, one is denoted by a .f, which I presume means its a French version of the DVD. The only difference here is in the UPC and Catalog number. My bet is one may have (guessing) French subtitles, and the other may have Spanish. They both say they use an English soundtrack.

It is interesting that they list it as having DTS, which doesn't appear to be the case for R1 discs. You are probably better off getting this from amazon.ca, and applying a coupon.