The V551 is a great phone, speaker phone, bluetooth, tri-band, world phone, camera are just some of the things that the X427 doesn't have.

The only thing I dislike about the phone is when you add a second phone number for a fax, cell number, email address, whatever, it uses a different line in the address book. The 427 puts them all under one name and puts a icon next to each number.

I've never had it drop a call but I've only had it a week or so. My order would be V551, 180, x427, V400, 220 last because of all the complaints I've read about that phone.