This is a copy of the Big E is from copy-righted Tamiya molds. The quality is the same as Tamiya. I have both versions of the Big E from both companies. The only difference I can see is the color of the plastic.
The MH Enterprise is motorizable, but the switch for it is located right through the #3 jet blast shield.
The story I got from the hobby shop owner where I bought the MH version was "chinese modelers wanted the Tamiya Big E, but they really can't afford the steep price for it". So MH came along bought the copy right from Tamiya and started producing it.
The BBs are the same. They are package from MH but are Tamiya molds. Even the airwing aircraft are the same as Tamiya.
One big difference is the Instruction book. Tamiya's is detailed, where as MH is just 6 pages.
One other difference is, I live here in Singapore and picked up the MH Big E for only 75.00 Singapore dollars. That equates to about $44.00 US.