On raw performance might, the M4 really does live up to Apple’s promises, should deliver. Single core is up about 20% compared to all M3 chips and more than 40% compared to M2. The generational computational leap from the previous M2 iPad Pro is at least a 42% jump on single-core and multi-core.
I have an X380, it’s pretty decent for what it is. Sure, there are plenty of things I’d change (ram slots instead of soldered, 3:2 or 4:3 aspect ratio for the touch screen, maybe a bit lighter) but later gens actually have a few of those improvements. It’s not really a great replacement for an ipad, but it’s a pretty decent work machine (provided you don’t need a ton of power or ram).