I don't think slate roofs are that bad - our house is an exceptionally exposed spot and has a slate roof and we lose maybe one or two slates a year to storms. Our wooden windows and doors are a far bigger maintenance headache than our roof.
When I got to the part about wood windows it dawned on me that the author is less clued in than he lets on. Wood windows are a maintenance nightmare. You can't open them half the year in a humid climate, or all of the year in an old house that has settled. No window is going to last 1000 years so might as well pick one that will make you hate your house less in the interim.
And one or two slates per year is indeed manageable, assuming they are in an accessible spot. If you're unlucky they are not and then you have to get to the spot to apply your fix without breaking more slates, which can be quite a bit of work (remove slates to make a path to the spot, fix, then rehang all the others, and hopefully they were uniform).
I've had one storm bad enough in NL that we lost some rooftiles, which were fairly easily replaced. Since in the rest of the country people had lost whole roofs and other houses in the same street were in much worse shape and comparing with the few houses that had slate I'm pretty happy with my good old 'dakpannen', which are almost maintenance free (due to the angle of the roof).
The worst is thatched roofs. Those require pretty much bi-annual upkeep and tend to become rodent infested. They look pretty in the first 10 years, a bit garish in the second and depending on their state of maintenance horror shows in the last 10. I'll never live in a house with one of those, people like them for status but they tend to be people that can afford to pay others to do their work for them.
