I guess I'll chime in here
I agree the first couple batches of film were all crap! I've just sold all of my first flush stuff on eBay for about half of what they cost me and I feel preety lucky to have revcovered any money there.
That said the 3rd batch of PX600 and the new PX600 UV+ aren't bad. Yes you have to sheild them, and yes you have to develop them covered from light and in a pretty narrow temp range, but the results are quite nice and very stable if you can develop them right (I have a few images that have not shifted or developed crystals for a few months and I haven't stored them in a special way, just had them laying about and on the fridge). I actually use the hot/cold clip they offer with the temperature indicating stickers and so far it's working great. You can see my most recent images here:
http://greenstphotography.blogspot.com/Now for the color film, it seems that heat is they key as well as using a green filter to cut the magenta hue. The best results I've seen was from someone who put a green fliter partially over light meter of their SX-70 as well as over the lens. Then developed the film covered by a darkslide in a hot water bath somewhere near 100 degF or maybe slightly above. The colors were amazing and aparently the film is very stable after that. Haven't tried it myself. I think that is a bit much to do for instant film. Using a cold clip and covering the film like for the PX600 films is fine to me, I have to do similar things with the old Polaorid stuff to make sure it devlops right. But needing a temp controlled water bath to get vibrant colors is silly. That said I have seen decent results with body heat and a green filter. One of these days I will try expermineting with the few boxes of Push I have.
I did learn my lesson, so I don't buy right away anymore, I wait to see what results start showing up on Flickr. I didn't like the mis marketing at the begining, but I also want integral film to be available. The cost is high, but we are talking a niche market so I doubt that will change much. Though $15USD would be much nicer.
But taking all of that together, the films are significantly more stable and actually much more predictable these days. There has been real progress. By now pretty much everyone knows these films are a work in progress so you have enough info to make an informed decission, and the company at least for now seems pretty forth coming with the characteristics of the films, and if they fail there is plenty of info online. Of course they are going to market the quirks as "awesomenes", but you always have to see through the hype to try and figure out what the reality is with any marketing campaign.
These films aren't for everyone but personally I am starting to like them. I am looking forward to the two new films, though I hope they keep the PX600 with the sepia and brown tones around cause I would like to have that option. I still want to see the films less sensitive to temperature because I want to be able to use them in the heat of summer around here (east coast of US) with out needing to carry around a bag of ice.
I am no lover of Impossible, I don't think we are ever going to see films like the old Polaroid Integral again. I have a decent amount of hope that Impossible will be able to make useable, and stable films and therefore I will have something fun to put in my SX-70 Sonar
That in the end is all I really want. I love that camera and came to instant photography only in the past few years so I just want to be able to keep shooting. I am not a fan of the Fuji integral films, but that's just me.