netTALK vs Layer Four Solutions

I've had the NetTalkDuo device (2nd gen) since 2010 or so, bought for $49.88 at Walmart. Included was 1 year of service. It's more of the Plain Jane type, no BT or WiFi, yet it's worked flawlessly for the past 12 years! Best of all, a full year of service of netTALK is about the same or less than a month of AT&T service (at that time). Actually was about $10 less after AT&T's extensive list of taxes & "regularity fees", which could easily be $15-20/month in itself! I hope the device lives another dozen years, keep it dusted and in a cool place to draw heat away. About some who are complaining about call quality, there's a recommended list of compatible routers for the non-wifi devices, this is likely the cause of some issues. I was using a low cost TrendNet router which was on the list & it worked perfectly. Later, went to using Linksys routers, all have been fine with my DUO device. Plus use a CAT 7 patch cable long before many heard of CAT 6, to shield against noise. For sure, when this one goes out, will get a newer model, hopefully price will be the same. I deeply regret that I didn't buy two of these, as were on promo at the time, regularly priced around $65-75 in 2010.