Speaker Output for Subwoofer--Sounds Better

I find using the a neutrik subwoofer cable at the subwoofer input to speaker terminals of the amp/integrated amplifier sounds better than using line level or dedicated subwoofer out (dedicated subwoofer out on my primaluna dialogue hp integrated).

I know REL seems to like using speaker terminals as it thinks it gives the subwoofer some flavor of the amp. Other than that, I see very little out there on this subject.

I really prefer using my three integrated amplifiers with speaker terminal outputs to the subwoofer.

Does anyone agree, disagree or have knowledge on this issue?
It's one of those personal preference issues.  Many prefer using speaker terminals. 
Brian Ding gives you the choice of speaker level or line level on his Rythmik subs' plate amps. One advantage of speaker level is the lack of needing another line level output on your pre-amp/integrated amp/receiver. His personal recommendation is line-level, for technical reasons he covers on the Rythmik website.
Thank you for the source.  It looks like it's a preference thing and maybe system dependent.