The good: they're definitely cheaper, I paid about a third of the raspberry Pi 2 price for a comparable Orange Pi. Other models seem to have similar aggressive pricing.
The bad: Armbian distros are a mixed bag, I had the impression some of them were put together by developers who didn't even have the particular board on hand. I spent a good three hours just getting WiFi to work (not being familiar with linux didn't help either though) , while putting up with an invisible cursor editing config files. Setting up a raspberry pi zero W in comparison was 5 minutes. Also I found out later that the pin header was 180 degrees rotated compared to the Raspberry, which made it not compatible with standard hats.
In retrospect I did learn a lot, and the Orange Pi has been running without issue for 2 years now. But Raspberry's have my definite preference.