Migrating from 3.0 to 5.0

I'm finally migrating to Deviation 5.0 with a new transmitter after many thousands of successful flights with 3.0.

My needs are simple - I only use DSMX and DSM2 with Spektrum, Orange, and Lemon satellites. No telemetry. I fly helis only. I use Devo 8S and 12S transmitters. No glitches ever with 3.0. I also want the old GUI.

Would the 5.0 release from 2016 be suitable? Were there any DSMX issues that a follow-up version addressed? 3.0 worked perfectly with the receivers above.

Thanks in advance and keep up the awesome work.

Many thanks for the reply Vlad - very helpful.

If I've already installed v5.0.0 release, do I need to re-flash with an updated DFU or will copying the filesystem suffice?

What are the XMS files?