We first saw Toshiba's XG5 M.2 SSD at Computex this year but as of yet we have not had a chance to review it.  The Tech Report on the other hand did get their mitts on the 512GB model of this drive and they put it through its paces in this review right here.  Their results show a drive that beats OCZs' RD400 across the board and is impinging on Samsung's 960 Pro and EVO, though they are not quite there yet.  The next generation will improve on performance which should spur Samsung to new heights with their next NVMe product.  At the start of the article is some history on the current state of Toshiba which is worth checking out if you are not familiar with what is going on there.

"Toshiba's XG5 NVMe SSD is shipping to the company's OEM partners now. We run it through our test suite to see if the company's newfangled 64-layer BiCS NAND helps it compete with the best in the business."

Here are some more Storage reviews from around the web:

Storage