I have all 3 models, the D70, D50 and D40. I like them.

They are standard SIP phones. You can use the phone GUI to configure the phones to use Asterisk. I configured the phone to connect to my FreePBX 2.9 distro in about 1 minute.

The new Asterisk -phones branch adds DPMA to use the advanced features of the phones like the visual voice mail, etc.

I can't speak about the features that need DPMA since I have not used it yet. I have only had the Digium phones for a week and have not had much time to play with them.

DPMA requires the -phones build of Asterisk and I do not think that is part of FreePBX distro yet. You could build your own system by hand and not use the distro.

End Point manager does not have configs for Digium phones yet so out of the box EPM will not configure the phones.

I would compare the D70 with a Polycom 550 or 650 with a side car. The D70 has 6 line appearance buttons on the phone and 10 buttons on the side car. There are two small buttons below the 10 on the side of the phone used to scroll left and right so you have sort of a virtual side car with many buttons. However I don't find this are usable as a Polycom 650 with 3 side cars.

There is a slot on the side of the D70 that appears to be designed to add additional side cars. there is also a jack on the back of the D70 for expansion so it looks like there is the possibility to add more buttons with additional side cars. I know of no plans from digium to add a side car but it looks like it could be done.

I have not really done a comparison yet. I have not had much time to really use the new Digium phones yet.

I have the D70 phone. I find the sound very good - especially when using the speakerphone. I did some tests calling into my voicemail and left voice messages to test sound quality. The outgoing sound is not as high quality as the incoming sound. I found my Cisco SPA phones had much better outgoing sound quality. The mic in the receiver very easily picks up air noise when speaking which comes cross as a cheap phone sound. The incoming sound has good bass and clarity.

I am disappointed that I cannot get the sidecar buttons to behave as BLF keys. As mentioned you need the special Asterisk version unavailable through FreePBX to install DPMA. There's no way that I know of to get the buttons to work as BLF keys through the GUI interface. By adding contacts to the phone, it sets up speed dial entries to the side car but that's it. There's no way to code it to watch for the Asterisk hints.

The font is small and hard to read on the screen. Maybe I'm getting old, but it's not just the fonts. The resolution on the LCD screen is poor. I'm comparing it to the LCD screens on my Cisco SPA504G phones. I can clearly read it, whereas this Digium phone I need to move very close to the screen to see it clearly. There are brightness and contrat buttons but they don't seem to do much as far as making the letters clearer to read.

The timer comes on when you are on the phone chatting, but the current date/time is only visible when not on a call. There's a lot of wasted space on the screen where the date/time could easily fit. Especially with such small fonts.

When hanging up the receiver it's a magnet that actually causes the hangup to occur. There is no switch hook button. I thought that was a nice design.

Overall for the cost I don't think the phone is worth it unless you had the special Asterisk version that works with the phones. The online GUI interface has some bugs. It's really lacking functionality/settings. I was expecting a lot more from a 2012 VoIP phone. Since I haven't been able to get the DPMA working, I cannot comment on that. If I try to install it I get this:

root@localhost modules]# asterisk -rx "module load res_digium_phone.so"
Unable to load module res_digium_phone.so
Command 'module load res_digium_phone.so' failed.

Right now the side car is just a list of speed dial buttons.

The GUI Interface is temperamental. Sometimes it will lose settings. I upgraded to the latest version and still lose entire lines/extensions that were provisioned just by simply changing the dial plan on one of the lines. Line 1 never seems to disappear, but all other 5 lines are set back to default and extensions, passwords, station name, etc are all erased.

I'm disappointed in the Digium D70. I definitely expected more. The polished videos make the phone seem excellent but I think there's much more value going with another brand.

That's even worse!

I don't know what they are thinking, but I'm getting rid of this $350 paperweight. eBay here I come! My fault for not waiting until people wrote some reviews. I searched a lot over a 2 week period and decided to trust the Digium Videos along with the sales department. I called Digium and the sales guy told me it would work on any Asterisk platform or on their Asterisk appliance Switchvox. Obviously he was misinformed.

It's the most expensive VoIP phone I've ever bought, and it's got the worst functionality. It seems it's more of a ploy to get people to buy their support. It's really sneaky to hide this vital info. Yeah sure - it works with Asterisk. Just not the Asterisk that you and I are using. :-)

The Cisco SPA525G2 beats the pants off of this Digium D70 phone. It's less expensive too if you look around!

You can run the digium-phones version of Asterisk with FreePBX. I have done it and it works fine. No conflicts as far as I can tell. Probably don't want to use the digium auto configure and Endpoint Manager at the same time for obvious reasons.

I don't have a problem with how Digium is doing it. I hope they can make some money at it to help keep the Asterisk project well supported and open.