I recommend the NEC because the customer can get true key system capability, flexible extension numbering, new phones, built in music on hold, built in voicemail (128 mbox), auto attendant, email forwarding and a 5 year warranty. Also one pair digital stations means no need for new cabling (Who else is making digital phones these days). Why continue to use a phone that may be 10 or 20+ years old? Depending on the business some equipment is filthy. Some people just want something new, some don't. No system is perfect and everyone is different. The transition from a Norstar phone to a NEC phone is minimal. I make sure the customer doesn't lose any capability and takes advantage of new capabilities. I still service BCM and really old Norstar customers and happy to do so.