I've bought a lot of Harbor Freight tools over the years to use in home garage/hobby use. Before I purchased them, I would often inquire on various websites and get mixed reviews, many times by folks that hadn't ever actually owned the tool.
I got on one woodworking website where many of the hobby woodworkers used HF woodworking and other tools. What I found out is how to read someone's expectations of tools and that many HF tools were quite decent for the price, especially for home owner use. The tools could also be improved very easily for very little money.
I have quite an extensive home shop of tools now, most from HF. With many of the tools, I took them apart, cleaned the interior, inspected them and lubed them with American lubes. This eliminated most of the problems people had complained about the tool on the web. On tools I got that were junk even with cleanup/inspection, I simply returned. If I had to buy "the best" or "name brand" tools, I wouldn't have owned very many tools. Couldn't afford it.
I just checked the HF website on their boat trailer offering. Biggest real complaint was missing nuts and bolts. Since the bolts are not likely to be stainless steel, I would probably replace them anyways. Most all the reviews were positive with most owners happy with their purchase. I would grab a 20% off coupon, wait till the trailer is on sale and get one if I needed a trailer and there were few in the local area.
What I learned from the experience is HF has many "gems" if one takes the time to research. These days, they have reviews of the stuff they sell on their website. If you take the time to read each review carefully, closely watching for not only what they say about the tool, but their experience and expectations, often times you will get a good idea of how the tool will perform in advance.
IF I needed a trailer and couldn't find one in my area, I would go to the HF website, look over their trailer offerings and find out what the reviews have to say. If many of the reviews are good, I would certainly buy one. By the way, read carefully the negative reviews and see if it's a trailer problem, a packaging problem, a lack of mechanical ability problem or an expectation problem that causes the negative review. This helps a lot in sorting out the real meaning of their number of stars rating. To be honest, I no longer go by the stars rating, I just reach all the reviews and see what the reviews tell me. Hasn't failed me yet.
Just my .02,