First, I am not a 'whiz' at all of this communication stuff so please excuse any technical errors that I make.
I have tried a few 'data only WiFi 3G/4G' setups like Dell Voice, Sipdroid, Talkatone and I can't remember all the others.
I found that the reception & voice quality, unless I am at home hovering around my router, is very spotty, and, not pleasant.
So, the direct answer to your question is, yes, iptel + ipkall + GV gives me a much better telephony experience, and, for the people that I speak to also. This, I believe, is because all my calls are over the *cell phone network*, not the data network.
Right now I am testing the voxox.com + GV configuration and it works just fine. I am using this configuration because you get a free US number from voxox.com, that you forward to your cell phone. You use the voxox.com number in GV.
The big benefit of a 'data only' setup is that you do not need to pay for 'unlimited incoming calls' with you cell provider - you just need to pay for data, which is cheaper than minutes.
With GV, you use just a tiny bit of data to initiate the call and then you're off data and back to the cell network.
All of this because GV nullified forwarding to my freephoneline 403 area code number!
There maybe additional advantages in using Dell Voice but reception & voice quality are what is most important to me.--