ThinOS v9 vs v10 for Optiplex 3000

Hi, I have some questions regarding ThinOS v9.x vs v10.x

The situation:

New Optiplex 3000 comes with ThinOS v.10.x, our current devices run ThinOS v9.x.

I can see that latest v9.x is released later than V10.x.

We we like to run same ThinOS v. across all Optiplex 3000 devices. 

Questions:

• Which benefits are there in v10.x compared to v.9x for Opteplex 3000?
• If there are no direct benefits - is it possible to downgrade from v10.x to latest v9.x?
• And why is v10.x not available on the "normal" Optiplex 3000 download site? (Support for OptiPlex 3000 Thin Client | Drivers & Downloads | Dell UK) The servicetag is one of the new machines running v10.x. <To protect you, your private information was removed from public view. All private data was saved to your private Case. DELL-Admin>
• It can be found at ThinOS 10 2502.60 Firmware Upgrade Package | Driver Details | Dell UK, where it says "for upgrade from earlier v10.x.". Does that mean I can not use the pkg for upgrading from v9.x?  

Hope someone out there can answer :)

Br. - Carsten