JFND wrote

They still work and yes we can finally update the names of the devices but the NTP server can't deal with DST,  Automated backups fail and email out of it is real iffy.

This has been already reported to TP-Link by several users.

Not too much trouble but if you decide to revert you're going to have to do a hard reset on the eap225's.  There is a new secert password assigned to them and the controller with the older firmware can't adopt them with the new firmware.

Not sure what you mean with »secret password«. Of course, the device account should be different from the default »admin/admin«. I accustomed myself to setting a secure device account as one the first steps everytime I did install a new controller, b/c in old version the controller did choose the controller's own admin password for the device (what was a bad idea IMO). 

You can downgrade the EAP's firmware with SDN Controller. As for adoption in the old controller:

If you did migrate the old controller to the new one, the device account should remain the same. No need to write it down.

If you did set up the new controller w/o migrating, you can find the device account under »Site« and can make note of it:

There is no »secret« device account.

jbtibor wrote

I didn't have to adopt the APs at any point, they were included automatically after I restored the controller settings from backup, just couldn't manage them until FW was updated.

Of course, if you did migrate the old to the new controller, there is no need to adopt the EAP since it is known already to the new controller.

Adopting is just needed if:

1. the old controller wasn't migrated to the new one and the EAP appears to be »managed by others«,
2. the old controller still runs and the EAP appears to be »managed by others«,
3. the EAP has been reset to its factory default settings which includes new EAPs just added to the new controller.

Reef-a-Holic wrote 

so windows version only not the OC200 hardware box?

SDN Controller is available for Linux and OC200 as well. See the international support site:

https://www.tp-link.com/en/support/download/oc200/#Firmware

https://www.tp-link.com/en/support/download/omada-software-controller/#Controller_Software

Note that you still need to download the SDN firmwares for the EAPs from your regional site (US/EU/CA or whatever).