My TC2s arrived yesterday so, as promised, here is update as to how I got on.
I wired a 1-gang in our bedroom and a 2-gang in the living room. Keendark, you must have had a faulty one as (having seen it for myself) there isn't much you can do wrong. Don't try it again - send it back!
If you are thinking of buying the TC2s, I did notice a very slight hum when the lights are off (with your ear right next to it). These things bother me a lot (especially in bed) but it was no where near loud enough for me to hear across the room in the night. If your switch is RIGHT next to your bed it may be an issue if you are a fussy-pants like me (I can't have a wireless phone charger next to my bed due to the noise).
When the lights are on, the TC2 noise drops to a barely perceptible 'purr'. The sound was consistent between 2 units (no louder for the 2-gang) so I wouldn't expect to see a massive variation.
This certainly would not stop me buying more of them and I highly recommend them.
I have had some issues in the past with RM Tasker not responding to Alexa voice commands but I seem to have fixed that now.
I use an AMLogic-based Android set-top-box (a Cooleme MB1 from BangGood). There are lots of cheap versions of these kicking around and they all have pretty much the same guts.
I had the box connected to WiFi, as I had heard that RM Tasker needed to sit on WiFi to be detected by Alexa.
I had issues with this setup because the WiFi kept dropping - maybe some sleep mode I couldn't find (I had told the device to keep the screen on in developer options but that didn't help).
Anyway, I eventually switched to a wired Ethernet connection and haven't had any problems since.
After switching to Ethernet I deleted all the Smart Home devices from Alexa and tried to re-discover them. I had to try a few times and it took a while (a couple of hours) before Alexa would see the device again. This seems normal as I had the same issue when I switched from running RM Tasker on my phone to using the AmLogic box.
It's a bit of a pain using Ethernet as the Broadlink e-control App specifically looks for WiFi to share codes, so when I make changes I have to switch to WiFi for a few minutes, but it seems to be much more stable in normal use (which is a critical WAF).
I now have the bedroom and living room lights running, voice activated by Alexa. It's pretty quick too. takes maybe 1 -2 seconds after the voice request before they switch.
Now, when I tell Alexa to 'Turn on Projector Settings' it turns off the TV, turns on the projector, makes sure the amp is on the correct input, sets the volume to 'quite loud', switches the raspberry Pi HDMI out to the projector (IR HDMI switch), waits for the projector to warm up then switches the projector to the correct HDMI input and [now] turns the lights off. I love it!
I'm doing all this with a Broadlink RM Pro, AMLogic android box, a TC2 light switch, RM Tasker and an Echo Dot - £140 for the lot!