I am a light user, do not play games, have special needs for large screens, high power, especially in the United States, there is almost no high-end call tablet. Advantages: M8's CP value is very high. I often draw web pages, watch youtube, use LINE, and pay by barcode. These requirements are sufficient to meet the needs of the M8. The system is very stable too. It's very power efficient. There is no need to turn on the power save mode. Light use + standby can be from morning to night.
I bought it for my son to watch TV. It is very convenient. It can be inserted into the card. It can also be called out if it supports 4g lte. It can replace work when the phone is out of power, which is why I bought him. And it is very cheap.
Not worth it we had it less than 20 minutes before it started locking up and glitching. Honestly don't know how the battery life was because it wouldn't work long enough consecutively without freezing.
I've been through a number of 8" tablets with phone capability. Most have puny memory (1GB/16GB) or don't get a reliable 4G signal. The AllDocCube gets a reliable T-Mobile 4G signal, has 3GB/32GB memory (not a terribly large amount but adequate), has no problem getting a WiFi signal and 'feels' pretty robust.
Would give 5 start but battery life is a bit on the short side - even with WiFi turned off. On the plus side it charges pretty fast...
If you're looking for a large phone with adequate memory/display/WiFi for 139$ hard to see where you would go wrong with buying this.