Well, I have to give it to the Suvolt. It surprised me. Whilst the magnetic connection feels very weak and doesn't feel like it'd handle much in the way of sharp shocks, I wound the coilovers on the car up to full back breaker mode and mounted the phone completely vertically. I've had various errands to do today and come across plenty of potholes, bumps, lumps, and those really annoying black and white speed bumps that are really short and really tall that bounce you off the ceiling - didn't even get close to budging. Very impressive. I don't think that without the magsafe case (I'm using Zeera's own) it would stay put with those bumps, but with the case on it seems secure.
As for charging, the C-C cable turned up and voila, magsafe animation and whilst I've not tested the speed yet, it definitely seems to be charging at the 7.5W Apple caps third party chargers to, if not faster (I know others have seen it charging at 8-9W). I'm not particularly keen on charging much faster than that, it's plenty enough that I can have Waze up and it charge my phone on a long drive. Besides, I've got the 12W USB-A which I'd like to think works when you connect a phone directly to it, seeing as it evidently didn't like the Zeera.
Ultimately I think it's redeemed itself. I'm not entirely sure you couldn't get the component parts separately for less, but IMO it does what it says on the tin and I'm happy with that.