Windows 7 - Google Voice/Obihai Adapter

This question somewhat covers the gambit between hardware, software, etc., so I chose the General Discussion board to post in. As a person that was thoroughly disgusted with Skype, and have been looking for an alternative, this device caught my eye:

Obihai’s OBi110 VoIP Phone Adapter Makes Your Home Phone Google Voice Compatible – Sans Subscription Fees | eHomeUpgrade

However, even after watching their videos, I'm still a bit confused. I have both the internet and my telephone service through my cable connection. Since it appears that this device needs to have both an ethernet, and a phone connection, would it work properly if I did so by connecting the PC via ethernet, and the cable modem's phone connection to the adapter?

If I understand, all domestic calls through Google Voice are free, and the adapter is only a one-time purchase, so I could make calls anywhere is the U.S. for free, as much as needed...right?

EDIT: Another thought occurred...I strongly rely on caller ID, doe Google Voice offer that?

google voice does caller ID as well as call screening with a voicemail listening in feature.
If you screen your calls and send the caller to Voicemail, you can listen in and then choose to answer the call if you need to.

That is good, but will it work properly with the PC and modem connections that I mentioned? If I understood the videos, you can assign different ring patterns to two different Google numbers, so I assume the same could be done between Google Voice and a regular land-line call...yes?

I guess that no one can answer the part of my question that is unanswered, so I went ahead and ordered the adapter last night. That may be the only way to know for sure.

I received my OBi and installed it. It tested okay on the OBi website. Since it was necessary to enable Google voice to use in conjunction with this, I did so, and made a test call to my apt. manager, which was successful, at least in terms that they answered and I could hear them on the PC. Now I must somehow enable it so that I can dial a number from the telephone itself, but since it can either dial via OBi or landline, I don't understand how to choose which? I will keep experimenting, but I wouldn't object to a helping hand.

Yikes! I just tried to place a local call on my telephone, and I got a recording stating that "There's no service available to complete your call". I never suspected that this would interfere with making local calls, which is even more important than long distance. I feel that all of this will work together, if I understand how, but if I don't figure it out soon, I may have to disconnect the OBi.

you probably need to use the area code when you call local numbers.

Yes I do use the code, it is now required even when using regular phone service. I believe the problem is with configuring OBi Talk online, but I'm going wrong somewhere. I posted a question about it on the OBi Forum, but haven't gotten a response yet.

I think that I got it fixed, I used the Google Configuration Wizard found on the OBi website, instead of entering the config manually. At least I did make one local call without getting that automated message. The only thing that I don't like so far, is that there appears to be about a 30 second delay after entering a number, before it starts dialing. There is also about the same amount of delay on incoming calls before the phone begins to ring.