I'm currently fitting Catnic Urban to our roof, which has a 5 degree fall. I have nothing to compare it with, and obvously can't comment on longevity. But the coating has a reassuring, appearance; as if it is lightly embossed with a pimpled roller, and seems very thick. The steel is much sturdier than I expected, and the panels click together very securely and look fantastic on the roof.
Apart from the look, we were drawn to Catnic by the excellent sales service, with an online estimator, which includes delivery. Despite being in north-east Scotland, delivery was possible and a kit arrived, including every last item needed to fit the roof, for around £8500 before VAT. The only negative is that obtaining information about fitting it was tricky, although a training day in Wales is available. We struggled to find anyone locally who would fit it, but as advanced (in experience and years) self-builders we've found that getting the 8.5 metre panels on the roof has been the biggest challenge.
I'll try to remember to get some images tomorrow.