Each customer/user is different. For me, it would be a disadvantage to me having a VOIP phone vs an analog adapter and using traditional analog phones.

REASON: I have 10 phones in my house. I have my house wired into my VoipO adapter at the Telephone box point of entry. Meaning, I have the telephone wires from the phone company disconnected from the phone box on the side of my house, I have all my jacks wired normally, and I backfeed the voip adapter into a jack to fire up all the phones in my house.

For me to buy 10 VOIP phones could get expensive. I tend to go for higher quality techno-gear. IP phones can cost as little as $30, but can go as high as $500+. I don't need to do that for 10 phones. Not when I've got 10 really good phones around the house. BTW: I hate cordless phones and only have one that I use in the garage in case I have to have one. The other 9 are wired phone. Personally,,,,, I think a quality wired phone beats even the best cordless phone.

WARNING: Unless you really know what you're doing, I don't suggest doing what I did. I've been doing this for a living for more than 35 years and I think I know what I'm doing. There's many things that can go wrong if you don't know what you're doing. E.g. voltage from the phone company coming into your voip adapter; too many ringers drawing too much current from your voip adapter; etc...