Spent several months comparing Xinix with Yo Telecom, Berry Telecom and BT's VOIP offering. Xinix had better prices, shorter contracts (30 days rolling), better features, were able to let me test their online portal, and sent me three handsets to plug in and try, so that's pretty amazing service already. Thanks to Jalal for answering all the questions.
Signed up, phones were delivered (self-installation - I wasn't given the option of having them come out to make it work, but that's probably a Covid thing), the phone numbers were ported when they said they would and we experienced no downtime. We were given a temporary number so that I could test everything was working.
Bill has been brilliant, answered everything I've thrown at him about how to configure everything like call queues and time frames, and discussing various 'advanced' features that I wanted to implement through the phones network interface (turning off missed call popups, changing the BLF LED behaviour, how to auto-provision other parameters and so on). Some of the phones didn't auto-provision out of the box, but that was sorted with a factory reset. He didn't even shame me when I admitted I'd connected the handsets to the headset port on several phones and couldn't hear anything.
So it's all pretty darn good. But you'll notice only 4 stars, not 5. Why?
Well, I think the portal is not very efficient - if you want music on hold in a queue, but you want users to hear a ringing tone when they dial in, you have to add music, then add an mp3 of a phone ringing as an introductory message. If you want to import shared contacts, it duplicates existing contacts, so you either have to delete everything or only import new contacts. If you want a queue to behave differently at different times of day/week/year then you lose some settings that are available if you don't use the time frames. Call history doesn't look-up the company phone book to populate From with a name, so it's not always easy to see if contacts have called. Oh, and the call history doesn't show a call quality summary for calls before midday.
But the biggest loss of stars is currently the call quality. Inititally we were on a really sub-par G729 8kbps codec that sounds like a recording from World War 2. This is cheap, low bandwidth, and fine for most use cases, but it wasn't good enough to give the call quality we want. We're now using PCMA (which is the G711a codec at 64kbps) which is better, but still inferior to a normal PTSN/copper phone call. I've tried to get them to turn on G722 support, which is a wideband codec also using 64kbps, but that hasn't taken effect yet. My limited testing (and understanding) suggests that jitter and packet loss aren't a problem, and the QoS in our Draytek router appears to be working well (in so much that network activity doesn't seem to impact call quality).
I'm very happy, but it's not 100% perfect yet, merely 99%. But I am pretty sure that Bill will have sorted everything by the time most of you read this, and as such, even though I've only been with them officially since the 16th, I can totally recommend Xinix to anyone thinking about moving to VOIP.