Xbox Series X backwards compatibility is shaping up to be an absolute home run based on our testing so far - yes, every title we've looked at so far seems to hit their performance target when 30fps or 60fps caps are in place, games using dynamic resolution scaling can show clear improvements, while we're looking at anything up to a 2x multiplier in GPU performance in games with unlocked frame-rates. On top of that, there's an image quality bonus too: texture filtering is improved via enforced 16x anisotropic filtering. Loading time improvements are also significantly improved - and that's the focus for this follow-up coverage.
You see, there's one disadvantage to the next-gen dream. Storage space on the internal solid state drive is at a premium - Xbox Series X ships with 802 useable gigs on the 1TB drive. On the one hand, that's actually an improvement over the 781GB of Xbox One X's 1TB HDD (my theory: Microsoft uses its hardware decompression engines to reduce the OS footprint, the console decompressing system files on demand). On the other, with the 1TB plug-in expansion drive priced at £220/$220, fast storage for next-gen titles comes at a price premium.
But maybe there is a better place for your library of OG, Xbox 360 and Xbox One titles. Xbox Series X still allows for standard USB drives to be connected to the console, and there's no reason why you can't buy an off-the-shelf SATA SSD or even a faster NVMe equivalent and copy your back-compat library there. And in theory, there may not be too much of a performance penalty for doing so: older Xbox titles cannot access the low level SSD APIs that truly revolutionise storage performance, so it may well be the case that keeping old games on the new drive is actually a sub-optimal use of the space anyway.