What you have read is correct. Not all printers and print servers are compatible.

If you've already got an Apple and it's working, that's just fine. But, don't expect it to work forever and with any printer that you will buy later. That's not guaranteed.

If you have brand loyalty to a printer manufacturer, look for a server that they make. HP makes both wired and wireless print servers.

Personally, I'd use wire where I could and wireless where running Ethernet isn't practical.