Picker for Input Box works both with autocomplete and picker icon flawlessly. Input Box is far from usable option for multiple values - because of natural limitation to single line. Picker works with Multiline Edit Box too - except autocomplete. I understand it is possibly XPages limitation, not ExtLib.
It would be nice to have Multiline Edit Box with autocomplete functionality - very similar to current "To/Cc/BCc" fields in rich client.