LifeSize Phone 2nd Generation has intuitive interface, users love it. Specially the Cloud directory.
One small thing I miss, if I have to search for a Meeting Room (Call >> Meetings) and find out what is the extension (numeric) number of it.
Numeric numbers only appears momentarily when meeting room is being dialed and in ringing state. They should also be part of Meetings listing with Meetings name as they are available in Directory.