This communication from Dan Scott provides some insight into the current state of 3M self-check systems with Evergreen:

We just bought a 3M self-check (V series V3) in late December and have it running in production with Evergreen today. So I can't provide you with too much data on long-term likes/dislikes about the unit yet.

We're using it in a pretty limited mode for the time being:
 * barcode scanning only (the unit also supports RFID)
 * printed receipts only (although the unit supports emailed receipts)
 * check-out only (the unit also supports renewals and check ins)

As a bilingual institution, we like that it supports multiple languages.

The major con with Evergreen was that the SIP implementation didn't support UTF-8 data the way that the 3M self-check expected it to. I posted patches that fixed the problem for us earlier today at http://markmail.org/message/px3oadhokmybpuoy - so that shouldn't be a con anymore, at least with this unit.

The other con of the unit is that there is a very noticeable lag between the time an item's barcode is scanned and the self check provides any feedback to the user; it might be that the unit waits to get some confirmation from the Evergreen SIP server before popping up the "Getting item information" dialogue. Even if that's the case, I would be much happier if it immediately let the user know the scan was successful
and that something was happening and am going to submit that as a request for enhancement to 3M.

Similarly, there's a delay between the time the item check out information is displayed and the item is desensitized; if the user pulls the item away too quickly, the check out transaction is scrapped and the user has to start from scratch again.