Very freedom-respecting. Probably the only consumer NAS vendor with instructions on how to install linux (bare-metal) on the official wiki. Their x86 boxen are 90% normal pc... with the remaining 10% being a bit nuisance.
If you go with QNAP be careful with what you provide access to over the internet. QNAP seems to have security vulnerabilities quite often. It would probable best to only use a VPN to access any services/media on it.