Interesting? Yes, certainly, it is interesting how ignorant some cycling wanna-be technical writers are. There's a nice emotional touch at the beginning of the article with that whopping 37% in drivetrain friction when going from chain to belt. Yes, it is a huge percentage increase but still only 1 watt. Yup, one single watt more on belt than chain.
Then the real treasures pop up. Words like pre-load are used out of context and then the author gets really mixed up apparently not understanding that the load on a chain or belt comes from rider input. The harder you pedal, the higher the tension.
The test doesn't measure the influence of lubrication on a chain either. It is a silly, shallow, sorry article.
Belts and chains have their place in industry and each has benefits and drawbacks. In my opinion, a belt drive makes a lot of sense for city riders who commute in horrible slush during wet winters.
But, in the end, what is really interesting is how the OP could "sense" 1 Watt and how much it slowed him down - so much that he had to get another bike.