here is the pics:-


-to tell the truth i don't even know if this chassis already for sale...well ofcourse the Tamiya TA05 is already on sale but the drift conversion kit from square...is it already on the market out there?? some people say it is a work in progress but some say it is already out in the market. so talking about the chassis roughly...the engine is located in the middle front of the chassis, the battery is places across the chassis to make the weight more stable. Oh ya i almost forgot to mentioned that it is a belt driven chassis.
I never tested any of the two chassis...but from what i see from both of the picture, i would say that the Tamiya TA05 with the drift conversion kit has more balance weight distribution than the Hpi Pro-D spec R. Thats all i could conclude. i don't know hows the handling of either both chassis but i think they would have superb handling due to the balance weight distribution.