I purchased this camera to replace my broken Cycliq Fly 6 which broke (twice).
The hardware quality is excellent and the tall slim design works well with a seat post mount, although I really don't like the mini-twist-mount, it's not compatible with anything else and there's no converter to a standard size twist lock mount. The buttons on the top are easy to access and press, although the images for 'power on/off' and 'photo' are black on black which can make it challenging to see which button to press to turn the unit on/off vs take a photo. That said, once I learned which buttons do different things, it becomes intuitive to know how to take a snapshot and power on/off.
Another comment about the mini-twist-mount. It comes with an angled rubber pad for your seat post mounting. This pad doesn't work well with flat-backed seat posts like are on the Tarmac SWorks and Shiv TT posts. The result is that the camera will occasionally shift left to right or right to left while riding on bumpy terrain.
The battery lasts a very long time. My typical weekend rides are 4-6 hours and it's good to know I'll have it recording until the very end.
The rear light is very good, bright, and has a nice variety of flashing and solid modes. I like that it has 3 light bars and they face in different directions.
The video quality is also very good and has a high level of detail. The wide view angle is adequate enough to get everything in the shot; vertically and horizontally.
That said, the interface to access the SEEMEE DV his absolutely horrible, bordering on UNUSABLE! It has a WiFi interface so you can access it from your mobile device, but their Mobile app is literally unusable and practically never connects. If it does, it loses connection quickly and files don't transfer from the device. I've located some other cheapo mobile apps (CAR_DVR) which does connect to the SEEMEE but that app seems to be abandonware. The only way I've managed to get images off the SEEMEE is by removing the micro-sim and putting it into my PC and copying the files manually. There's also no easy way to update the firmware on the camera.
Overall, this is a great camera with a great design and has very good features. I would recommend it for those reasons, but the UX for getting the data off the device is bad enough that I can't give it a 4-5 star rating.
Suggestions for MagicShine: Check out the GoPro Quik mobile application which is rock solid and has a very good user interface and experience.