Were ADAT converters highly rated? Should I (better late than never) seriously upgrade my Delta66, to say a Lynx L22?
To return to your original query I'd say you'll notice a huge difference between an elederly Delta 66 and a Lynx L22.
I've reviewed both and the L22 is nothing short of superb for audio quality. The Delta 66 was a good card in its time, but seriously outclassed by most budget audio interfaces nowadays, and particularly by the L22.