Well its just an amateur investors opinion piece, its no different to reading a poster's opinion here on HC. (well, except these freelancers are paid a small amount to write these 'articles'
His comment, "although for me it doesn’t tick enough boxes to make it investment grade." is what i recently read described as a 'deepism' - it sounds profound at first, but when you analyse it the comment is meaningless.
What metrics make it fail as an investment grade company?
Certainly none of the metrics I use raise red flags, the biggest issue with understanding TGR is as craft pointed out, how you deal with the capex requirements of this sort of business in your valuation.
In saying that I wouldnt be looking to build my position with the price over $4, but happy to hold.