Bests & Worsts Reviews from Amazon

Something is very wrong with these Micro SD Cards particularly from this seller/page. Despite the saying "Made for Amazon", I suspect these might be counterfeit. Here's my assessment: First off, I have purchased about THREE DOZEN Micro SD cards for various projects over the last three months for various projects here on Amazon. They have all been either 32Gb or 64Gb SDXC I versions. The makes and models have been SanDisk Ultra (as this one says it is), Samsung EVO (green and orange versions), Lexar Pro, and PXY. Of the over 30 cards I've purchased, I have not had a single issue on any one of them. In fact, I purchased a SanDisk Ultra 64Gb SDXC I card a couple months back under a different seller's page, and it's still working perfectly fine. Packaging: I ordered 3 of these cards from this seller page in two separate orders a couple days apart due to the low price. The first was delivered yesterday, and the following two were delivered today. Each was sealed in a tiny plastic-molded container, and placed in a cardboard envelope with SanDisk written all over it. By "envelope", I mean the plastic molded container housing the card flopped around freely. You had to pull the envelope tab to open it, and the container falls into your hand. This is VERY different from the SanDisk packaging I'm used to. The one I bought a while back here on Amazon from a different seller page. That one came like most Micro SD Cards packaged where the plastic-mold containing the card was then pressed firmly into a cardboard sleeve where you needed to cut around the edges to release the card. The one I bought a while back had the usual UPC barcode on the outside. These that came the last few days had no UPC bar code in sight. Performance (or lack there of): I build .img files for easy writing from a file to Micro SD cards for various module projects. I tried to write the same image file (.img) to all three of these cards I purchased. Two of them would write at a mediocre speed of 17.99mb/s, and the third at 39.99mb/s. Only ONE of the cards actually worked (one of the two @17.99mb/s). The other two could not be read. This was after multiple attempts. Only one of the three (one @17.99mb/s) actually works. The one that wrote @39.99mb/s did not work. Look (sketchy and looks counterfeit): Here's what seemed very odd. As I've noted before, I have a legitimate SanDisk Ultra 64Gb Micro SD SDHC I card that I've had for a good 3 months. I used it for comparison. These from this seller page not only had lighter and blurry coloring on the front side, but was exactly the same on the backside. Like I've said, I've bought over 30 Micro SD cards in the same class and size over months. I have not seen this kind of sketchy inconsistency for exact model versions. These are extremely sketchy. I would strongly suggest NOT buying them, at least from this seller page. Something is very wrong here.