I too am wary of the Moderators becoming too involved with choosing a replacement system although I would like to be able to explain my requirements.
My main requirement is that all of the functions that I need should be easy and consistent to use. Whist being a Mod gives me access to more functions on the current system many of them are clumsy to use or simply don’t work as expected or in the way intended.
In addition to user functionality there is also the question of the facilities provided by the forum software itself such as an easy way to post code without it being interpreted as HTML. Discourse supports the use of BBCode and hence code tags, which I have tested, but as the majority of first time posters don’t use the easily accessible code tag icon now I hardly think that they will add code tags manually. Can Discourse be set up to allow a code tag icon to be available or perhaps even to spot that a post contains keywords such as setup() and loop() and trigger a reminder to use code tags ? Could it be set up to recognise foreign languages and check the forum section being posted in ?
As to the migration of the current database, I have mixed feelings. To me the current range of forum sections is much too large. Many were, I suspect, set up on a whim, used for a while and are now dormant. I would support a clean break from the current forum which would be left in read only mode so that links to old posts could be posted for reference and/or copied to the new forum. A message at logon directing users to the new forum would, of course, be handy.
A clean break would allow the forum sections to be reviewed and rationalised. As has been pointed out, most topics have a relatively short “shelf life” and whilst the changeover would be traumatic it would surely be a good move as long as the new forum system can provide what we all need