I've got cover with World Nomads and have some customer service issues with them. Doesn't seem to happen to people elsewhere but then Aussie customer service is never the best. The biggest issue was that, when I wanted to extend my policy, the online option wasn't available and it took some mucking around to get the extension (in the end, I had to get my sister to call them on my behalf). Then, recently, I had to return home for compassionate reasons and they were very vague about it.
On the other hand, I had one claim with them and it was settled quickly.
Tbh, I don't think there are many other options.