From all the comments I've read, it really sounds like it's going to make more sense outside of the US. Here in the UK the vast majority of roofs are either clay tiles or slates which are expected to last 50 or more years, but the US seems to largely fit cheaper asphalt shingles and replace them more often.

At the moment our slate roof is fine, but when it needs replacing I'll certainly look into the Tesla tiles. Hopefully we'll be able to hold off for long enough that they will have come down in price. I'm sceptical that they will be worth it, but if they make sense then we would definitely think about it.