I did see film from the Impossible Project for the first time on the weekend - They were shooting fun Polaroids at a wedding we went to. The images took 20 mins to develop, and were somewhat underwhelming when they did. So the speed and color on the Fuji instax is looking good at this point - even though the prints are rather small.
I have a few ideas for longer term instax projects, so we'll see how it goes - I have 3 more packs of film in stock, so I'll blast through those and do a write up.
That would be interesting. There are two variants of the Impossible Colour film, one is much more vibrant and life-like than the other and is quite new. I haven't yet had time to shoot any of their 10x8 and I suspect it will be Xmas before I do.