Not really...it's a 14 minute video showing off footage from his new drone and a recitation from the Bergara catalog. Only two groups are shown, only one is from the BMR, and they don't tell you what ammo they tested. Typing "review" in the title doesn't make it a review video.
If the BMR is anything like the B14R steel vs carbon argument, they should shoot very similar. Personally, I'd rather not pay an extra $100 to save a few ounces on a rifle that is already incredibly light, but it's your money. A lighter rifle is fine if you intend on hiking through the woods with it, but it is a big disadvantage on a bench...lighter rifles are very easily influenced by very small amounts of body movement, which translates into larger groups. Also, it's not a "carbon" barrel...it's a carbon fiber tube covering a pencil thin steel barrel.
My BMR, steel barrel, shoots a 6x5 target average of 0.36" @ 50 yards with Center-X. Not too much larger than my B14R (0.30" average).