The principal differences between the fifth and sixth generation iPad Pro 12.9” are relatively minor internal hardware - albeit in some regions coming with a considerable increase in cost over the fifth generation iPad Pro.
The new sixth generation iPad Pro benefits from a upgraded SoC (M2 CPU) - providing some performance increase over that of the already stellar M1 CPU - plus updated WiFi that now includes WiFi-6E support. Unless you posses one of the very latest WiFi routers in a region that permits WiFi-6E - and have an internet connection that can benefit from the increased throughput of “6E” - the tangible benefit of this latter enhancement may be limited.
The only other additional feature is the new “Hover” function for the Apple Pencil. Until software is updated to utilise this new feature, it’s benefit is as yet unknown.
In summary, if you already have a fifth generation iPad Pro 12.9, upgrading to a sixth generation iPad Pro 12.9 will bring some additional performance over that of the already very-high performance outgoing model. If you have just acquired a fifth generation iPad Pro 12.9, you are very unlikely to be disappointed with what you have.
Speaking of personal experience, I am yet to encounter the performance limits of the iPad Pro5 1TB/16GB RAM - no matter what I try to do with it.
