Samsung announces 990 PRO NVMe SSD and Satechi releases compatible USB-C enclosure
Are all NVMe M.2 solid state drives the same from a performance perspective? Technically, no, but nowadays, even the lower-speed offerings are still rather fast. In other words, no NVMe SSD is "slow" although I would still caution to stick with trusted brands if you value your data. After all, it doesn't matter how speedy your drive is if it dies and your files are lost.
Samsung is probably the most trusted name in solid state storage. Not only are its SSDs historically very dependable, but very fast too. While a Samsung SSD may cost a bit more than some other brands, it is absolutely worth the premium if you want the best.