A great review found here:
Hisense Sero 7 Pro review: a newcomer tries its hand at Android tablets
mentions the "too hot to touch" level of heat. If that heat is coming from the battery pack, that's something that will greatly shorten battery life. If it's from the charging circuit with the heat making its way via conduction to the battery, that's still a bad thing for the same reason.
The multiple comments here about the charging connector coming loose also concern me and makes me wonder whether the price drop to $129 might have something to do with known (to Hisense) serious flaws. Heck, even the new Nexus 7 is having significant issues:
Nexus 7 problems: What users complain about most | Digital Trends
Thus, my rule of never buying a first edition of any mobile eToy or being the first to buy any new edition when it's first introduced.