We just bought the Telo system 2 weeks ago. I've got both the Telo base & a Telo handset. We've been testing the call quality between our current Cox Digital phone & the Telo. My wife often works from home & we wanted to make sure she wouldn't have any issues when she's on a conference call or whatever (I had read about the issue with conference call disconnects). The house is on a closed loop. All I have to do to switch is unplug the phone cable from the Cox Digital voice modem & plug it into the Telo.
The sound quality is flawless when we plug the Telo base into the wall & use our old 900mhz cordless phones (or wired). In fact, it even sounds better than the Cox line.
The first problem is we occasionally get DTMF tones. It sounds like someone pushing a button on the phone. It's random & doesn't happen every call, but sometimes it'll happen several times on one call. This happens on both our home phones & on the Telo handset.
The second problem is the sound quality on the Telo handset is terrible. It sounds noisy & I get dropouts or garble every minute to 2 minutes. I've already updated it's firmware. Range doesn't seem to affect it & I never get below 2 bars in the house anyway.
I've got some other gripes about the handset, like how it has de-synced from the base a few times when the base has lost power or sluggish response. Those things I could live with as I expect firmware updates will address those issues, but I'm going to return this thing if it continues to have this much garbled sound.