I was actually stunned to see Tamiya use the side mounted main belt and the front belt. I understand why they're using the geared drive in back but , for many, that means more things to go wrong.
I truly wish more effort would be made to promote the E4. Everytime I even think about trying something else or going back with my trusty old XXX-S, I look at this chassis, realise how well laid out it is and just how easy it is to work on, and suddenly the idea of changing simply doesn't make sense. It really is a great design.