I own all 3 of these... heres a little summary:
Ski Porn- does have some sick shots and segments, good music, however it is representative of its name. They named it ski porn for a reason cause its "just skiing no plot". There is no flow to the movie at all. Lots of bonus footage too, the second disc is kinda funny/good.
PUSH/PULL- Very typical of Matchstick, love them or hate them. Lots pow and lots of big mountain. Maybe a couple rails/boxes in the whole movie. Music is alright, just kinda middle of the road. Some sick sick heli footage of a huuuuge jump they made in whisler and a bonus feature on that segment. Lots of rider commentary and pretty good flow. you get pull as well but its just the same shots and same music edited by the skiers instead
LSS- I think LSS has the best balance of the 3. Lots of sick park with some pow and big mountain in there too. Not a huge variety of rails but the urban is pretty inventive, some cool stuff in there. Music is like it or hate it, some hip hop in there. lots of bonus footage, it fills a douple layer DVD. Vanulars segment shines... cork 8 on to a down box... sick.
Overall, my choice would be LSS. I enjoyed all 3 though and watch them all regularly. No, I dont want to suck off L1P, I wasnt that into Shanghai Six