I'm still only on my second pack of film but I've only had one picture that turned out completely black. I've found the colour film to be a lot more temperamental than the black & white.
The camera I use (Polaroid 1000 Land Camera) has a focusing distance of around one metre so selfies turn out really blurry.
Overall, I'm loving this camera so far. the size of the print is fantastic and I love the colour tones you get with the film. Each pack of colour film is different so I look forward to trying my next colour pack to see the difference in those colours. It's also really fun to have a black & white film pack as other instant cameras like the Fujifilm Instax currently only have colour film available (I shared a way to get black and white Instax prints here).
I'd love to hear your thoughts on Polaroid - is the cost worth it or is sticking with Instax the way to go? Which Polaroid camera do you have or which one do you lust after?