Is a good IP phone better than an ATA?

[sgarson]

Can anyone advise me as to the quality difference from using an ATA or gateway with my four office phones versus using IP phones like Polycom 301s or Snom 190s?

[ctylor]

Usually you can only register one device per SIP account, and so in this case, you would be limiting yourself to a single IP phone for the account, as opposed to setting up an ATA where you can continue to use your four phones with a single DID. IP Phones often have a lot of features, but unless you plan to also buy four different SIP accounts for the four phones, I would go with an ATA.