This review is very much a waste of time. It is more than a year after the the-digital-picture review for example and says less and gives less detail in more words. As for focal length, it says nothing about the performance with the 1.4x and 2xTCs, and doesn't even mention the latter. It says that one con is the weight, but it weighs far less than the 400, 500 and 600mm f/2.8 - f/4 primes and gives IQs not much worse than them with the TCs. The reviewer just doesn't realise that the high quality 300-600mm range in a relatively light package is what this lens is all about.
But I don't own a TC. I'd like to though 
You can't have wasted *too* much of your time on it, though, since if you did you would have read my statement "That’s why I wrote this piece completely from my perspective, from the curious photographer, wondering if I need just a little more reach. " Which is obviously not your position. I've never used a 300mm lens or a greater focal length, neither have many others, so I wrote it the only way I could, which is from my perspective.
A waste of time for an accomplished, well seasoned photographer whose used every lens ever made? Yeah, absolutely.
Your constructive note about it weighing less than a 400, 500 or 600 is appreciated though. Unlike your opening statement, I found that point useful.
If that was the purpose of your writing, then you should not have called it a review but should have chosen a more appropriate title. As it was, you led the reader to expect far more than you delivered. If you called it "My first try with a 300mm lens", then I would not have complained. But the simple title "Review - " without any qualification raised anticipation to expect what wasn't there.
Talk to the boss, it's his shop.
Though, my understanding of the term "review" is that it can vary based on that of the reviewer. While standards are met by individuals, are they not all of varying degrees of of both objectivity and subjectivity by both the reviewer and the discerning reader? I'm assuming not every review you read previously that you considered a review was identical to one another, words copied verbatim. Perhaps the findings were the same, it's hard to argue math if it's there, which is why I don't even bother including test charts samples, cup size and SAT scores - that's all out there for everyone to see. I'm not saying my take on the 300 was a particularly good one, just the best that I could produce. I even differ to this point in my closing sentence "And while my curiosity was piqued, I think for the more specialized super-telephoto focal lengths, I should step aside and let someone else handle those reviews."
Indeed, I won't be writing-opinions-that-pretend-to-be-your-definition-of-a-review because I'm not qualified to. I'm sorry I didn't live up to your expectations or standards, it's like my relationship with my father all over again.
To make it up to you, here's a photo of a duck I took:
