Interesting... so is that another one of those differences between Japan and US? Not having customer ratings/reviews?
Only from the perspective that there are few DIY people to comment on such products and if they do say anything Japanese are culturally very circumspect to state clear opinions. These products are intended for professionals who don't give up their secrets easily, and assuming such information exists it would be in Japanese, on an obscure forum and due to the language barrier impossible to
vet for accuracy and bias, etc... If you do a Google search on "Best Polyurethane" or even more specific search terms, we will get a plethora of English information. The results can be overwhelming, but we can see the context, evaluate the bias and intelligence/experience of the source and come up with a few good options to research. But as is often the case those specific products are not available here, and to try and emulate that workflow in Japanese is far more difficult.
The challenge starts with having to discover what they actually call this stuff in Japanese. Like the Steve Martin quote, "The French...they've got a different word for everything!" it may come as no surprise that the Japanese exercise a lot of editorial discretion on what they call something. Google is happy to directly translate "Polyurethane" to 'ポリウレタン' but that's not what they call finishes in this context, so if you try and search for that term you will get lost in a hellscape of irrelevant results.
In this case they misleadingly call it 'ウレタン' (Urethane, pronounced
oo-ray-tan) which is a very different product by Western terms, and led to several hours of confusion as I had to research the actual chemical components of the Japanese products to verify that they were in fact
Polyurethane despite the incorrect terminology. It can be so frustrating knowing what something is called, but then having to
battleship of all the possible ways that it might be called by Japanese (who are conversely always confused when we don't understand what to them is an English term, completely unaware of how badly it has been mutated by their transformation.)
Searching for it by the direct phonetic translation is always the first step, but it is rarely successful. This is often complicated by Chinese Alibaba companies just doing direct Google phonetic translations on everything so the right item shows up, but it isn't what it is actually called in Japan and that ends up muddying the waters. So if you are trying to find a "Slitting Saw" Google happily translates it into the Japanese phonetic equivalent, it doesn't give you the actual Japanese term for that item (they seem to call them スリワリフライス which doesn't translate to any English term I am aware of

) and all you get are a ton of Chinese results which are useless if you are trying to locally source the item.
So Japanese either have a completely local term (usually expressed in Chinese characters) some bastardised English term, or often if the object was first introduced to Japan from a different nation they might call it by some corrupted Portuguese, German or French name. Often you are searching without knowing if it is fruitless, that they really don't have such a thing, or if you just haven't found the magical incantation that will apparate it in your Amazon search. I've spent hours trying to find little magnetic vise soft jaws, floor leveling cement, wall mud, molly bolts and a million other items that are trivial to find in English.
So now you've found it, searching for 'reviews' of said item can result in either some fascinatingly detailed rabbit hole of obsessive Japanese nerdery (a good thing) or much more likely a scattered, ambiguous mishmash of comments where the stars given and the translated review often are in opposition and from sites that you have never heard of and don't seem related to the subject matter at all. Again, luck is a big factor here, in this specific case, lacking any useful public comment I made a decision based on the breadth of product available, my perception of the intended customer (professionals) and the unusually accessible product documentation (Japanese love to typeset everything into giant images, or only give instructions on the labels, which are of course nearly impossible to translate.)