Funny you should ask, Kamas! I finally posted a guide on just this subject last week:
VoIP and the return of the home phoneATA equipment is listed out on
page two, but I'd recommend reading the whole mess for context so you can better grasp what you should be looking for to meet
your needs. Reading it should help you get a far better handle on your entire pending system.
Edit: Waking up a little more, I realized there's still a bit unanswered to your question from that link. Overall quality? They're all prosumer ("professional" consumer) grade electronics and about equal on the quality front for the most part, so basically they're all made in China with CapXon or equivalent quality electrolyte capacitors and shipped with feather light power supplies. Expect to be swapping out a DC power brick or soldering in replacement capacitors or just replacing the device some time after their warranty period ends and before the five year mark. Unfortunately, "higher end" ATAs don't really exist as such because if small-medium businesses are running a VoIP solution, it's usually with a homebrew IPPBX server running
Asterisk or a
Trix Box with an SLA, or similar. Smaller businesses usually veer towards Cisco-Linksys because nobody gets fired for recommending Cisco, but their quality has not been much to write home about in the consumer end of the spectrum for several years now and the Linksys badge is about to get worse (says the dude on his second and probably last
WRT54GL over the past eight years - also, the Linksys brand's being sold off to Belkin,
yecch). I'll admit, I was lazy when my Linksys PAP2-NA snuffed it a couple years back due to two bad caps on the board. Instead of repairing it with a couple caps ordered off Digikey and rolling for a few more years, I just picked up a $30 Grandstream HT-286 instead, but overall both devices have had a good run without major issue for consumer-grade hardware.
Overall, any of those devices are going to provide reasonably equal call quality at all of those price points. Internet connection stability, codec selection and VoIP provider choices and
their call trunking choices are going to have a far larger impact than your selected ATA up until the point that the ATA starts to go south, and even then there's no guarantee that its failure will impact call quality like the PAP2-NA did with swollen capacitors right next to the FXS ports causing line static, it could just drop calls or not work at all. Most models fail in a similar manner at the end of their life, but each device model fails differently.
