I had an OWC Thunderbay 4-drive enclosure, that chugged along ok for a while, although I was never impressed with the build quality for the money. Then one of the Tb ports stopped working properly, and the drives would suddenly disconnect without warning. Sub-optimal. So I returned it, and as it was outside the 30 days thing, I had to accept a replacement. At this stage I had serious buyer's remorse anyway, as I felt it was a poor quality product for the price (very basic casing, poor manufacturing quality, no soundproofing, cheapo loud fan, rattly). Fortunately, the replacement was DoA, so I got to return it and demand a full refund; I claimed that the product was not 'fit for purpose' as the two copies I'd had were both very poor quality. I was dreading the retailer arguing and trying to fob me off with yet another one, but they accepted my claim and refunded me in full. So props to them. Put me off OWC products though.
Still needing some kind of enclosure, I bought a cheap Orico branded thing off The Internet™, which was surprisingly somewhat better in quality, although USB 3.1 rather than TB. Meh. It was a lot, lot cheaper.
Anyway point is, that if a product is faulty, it could be just one rogue item. 2 or more versions also being faulty could just be coincidence and bad luck, but could point towards a bad batch or just 'not fit for purpose'. So like more than one unit being faulty gives you a much better chance of getting a full refund. There's an awful lot of absolute crap out there in the consumer tech market; works ok for a while, then repeated heat/power cylces eventually leads to failure. Often outside of a warranty period. The problem with the '6 year rule' is how long a product is expected to last under 'reasonable use'. This is often quite an abstract concept; a manufacturer can argue that something like a set of headphones would only be expected to last two years, say. 'Lifetime' warranties are another one; they seldom mean the lifetime of the original owner. Such are quite popular in bicylce manufacturing for eg, but 'lifetime' can actually translate to just a few years. A lack of case law makes it difficult for any legal standards to be imposed on individual manufacturers, hence the 6 year rule. Manufacturers often have ways of getting out of having to cough up for warranties.
