Personally - despite being a very similar product - they are inherently different.
IF I was going to scrape gravel, dirt, pine needles or something - the Ratchet rake would be ideal! It is not a true digging tool - it can scratch and remove layers of top easily and I would say it will do it far better than the PTB.
The down side to the RR is that it is NOT a digging tool - it is a removal tool for something that is laying on a surface. Also - when you want to load the bucket with material it must be removed.
The PTB is a digging tool, it too can back-drag (not as well) as the RR but it's digging capabilities are unmatched.
I have had the PTB on my BX for 5 years......I cannot imagine NOT having it!
I have dug, dragged and cut and trimmed and you name it - it has performed perfectly.