I've tried both of these devices. The Digitone (and anything similar) is useless, as it requires you to press a button every time you receive a call from a "bad" number. I did this for about a week, logging hundreds of incoming calls, and I rarely saw a duplicated number. So you'll just be pressing the button all the time - might as well just pick up the phone and hang up.
The Sentry is much better, but has some notable flaws.
The Sentry works as a whitelist, so it blocks all calls by default. After you enter your whitelist (family, friends, etc.), you'll get three types of calls:
-Good Calls: From people on your approved list. These calls ring through as normal.
-Bad Calls: From idiots (aka robocalls). The idiots aren't smart enough to press a button, so they don't, and then the Sentry hangs up the call.
-Other Calls: From humans who are (ideally) not idiots, but aren't (yet) on your list.
This third item is where the Sentry really needs improvement. Other callers hear a (horrible quality) outgoing message, so they can either hang up, or press a key to leave a message - on the Sentry, not your answering machine/voicemail. The message they leave is only 20 seconds, and you can only receive two messages. And you can't screen these calls - you don't actually hear the person leaving the message, and you can't pick up the call if it turns out it's valid. And the Sentry doesn't timestamp the message. There's a log of calls, but you have to work to figure out who actually called, especially if the caller's message was cut off.
(What I would prefer is to have callers press a button, then my phone rings like normal.)
If you don't get a lot of "new" numbers calling you, the Sentry isn't bad. But you will miss some calls, especially at first. Thankfully, there's an on/off toggle for those times when you're expecting an important call from an unknown number (delivery guy, hospital).
The Sentry is much better, but has some notable flaws.
The Sentry works as a whitelist, so it blocks all calls by default. After you enter your whitelist (family, friends, etc.), you'll get three types of calls:
-Good Calls: From people on your approved list. These calls ring through as normal. -Bad Calls: From idiots (aka robocalls). The idiots aren't smart enough to press a button, so they don't, and then the Sentry hangs up the call. -Other Calls: From humans who are (ideally) not idiots, but aren't (yet) on your list.
This third item is where the Sentry really needs improvement. Other callers hear a (horrible quality) outgoing message, so they can either hang up, or press a key to leave a message - on the Sentry, not your answering machine/voicemail. The message they leave is only 20 seconds, and you can only receive two messages. And you can't screen these calls - you don't actually hear the person leaving the message, and you can't pick up the call if it turns out it's valid. And the Sentry doesn't timestamp the message. There's a log of calls, but you have to work to figure out who actually called, especially if the caller's message was cut off.
(What I would prefer is to have callers press a button, then my phone rings like normal.)
If you don't get a lot of "new" numbers calling you, the Sentry isn't bad. But you will miss some calls, especially at first. Thankfully, there's an on/off toggle for those times when you're expecting an important call from an unknown number (delivery guy, hospital).