You dont want to know what I think about most of the time. With regards to grass, it really does bog down a truck, even if its just a few inches long. Its like a person trying to run on a sandy beach- you quickly get warn out. I like the motor mount idea too- it would allow you flip the motor so its mounted more like this:
Credit to Candyman- old G1 chassis photo.
Obiviously with one motor, and you would need to either change the motor wires around or flip the diffs. But it would allow for more gearing options, and better weight balance apparently. Im getting the X-brace motor mount for that reason soon, but the way you have yours set up is rather cool. On the batts front, side by side packs seem to run cooler than end to end packs (the way they are soldered), so that might be worth considering doing too. And video, I want to see video.....