Bought this to replace/upgrade an old S450IP system. The C430H handsets are smaller, lighter and look better. The N300IP base station is faster to control.
Configuration options are good, with support for multiple SIP accounts, the fixed line and multiple calls simultaneously through the system. Handsets can be configured to always dial out from a particular line/account, or the user can select at call time. Calls incoming to accounts can be configured to ring whatever handset(s) you desire.
The phone system meets my needs perfectly and I would recommend to others. Using a BT landline in the UK and a SIP connection to a private Asterisk server.