I use a different cart (the Instep canoe cart with 16 inch bicycle wheels) so your experience may not be the same, but for nearly all terrain except going up the steepest of hills, I find it easier, with better control, to push and/or follow along as the case may be from the rear of the boat. This allows me to easily keep my eyes on both my path ahead and the wheels at the same time if I need to guide them around obstacles. This is also far easier when going down steep hills. And in July, on those Maine forest roads, all the deerflies and horse flies are looking for me at the front of the boat as I walk along to the rear.
-rs