I had a friend try VoIP on a dataplan a few years ago.
> The biggest problem I foresee is a lack of QoS,
Bingo. QoS for voice is about jitter and consistency of your stream.
> I'm hoping that best effort on a lower bandwidth stream will work alright.
Lets put it this way: you don't care if your webpage loads 0.2 seconds slower. But a few random 0.2 second delay in your conversations will make them utterly, and completely unintelligible. Low QoS is something data can afford because little "sprints" of high bandwidth is good for webpages and streaming video.
But "live", and "realtime" voice communications, the jitter is just too awful.
If no one else is on the cell-tower, you might be fine. But every now and then, you'll just get completely terrible phone calls that are unusable.
> The biggest problem I foresee is a lack of QoS,
Bingo. QoS for voice is about jitter and consistency of your stream.
> I'm hoping that best effort on a lower bandwidth stream will work alright.
Lets put it this way: you don't care if your webpage loads 0.2 seconds slower. But a few random 0.2 second delay in your conversations will make them utterly, and completely unintelligible. Low QoS is something data can afford because little "sprints" of high bandwidth is good for webpages and streaming video.
But "live", and "realtime" voice communications, the jitter is just too awful.
If no one else is on the cell-tower, you might be fine. But every now and then, you'll just get completely terrible phone calls that are unusable.