I am 5'10" and 125 soakin wet.
I started the game with a 13hp lt, it almost killed me the first trip out but before long it was like driving a 9.9 outboard.
Next was a 24 Honda which is about comparable to your 27, it was hard to handle the first time out but now its not a problem at all. I use my body and put my feet on the sides of the boat to turn it sharp. I don't let off much if at all to turn. Right turns are no problem, in a left turn I lean forward and pass the tiller behind me with my foot resting on the side of the boat. When it is time to get straight I use every bit of my ass to turn it back
I have found the hardest time to turn is at about 2300 RPM's off plane and bogged down, its also when I am prone to take water over the back.
From what a friend described when he owned the same 1644 GD boat, the boat definitely drifts on turns and like everyone said, slow down accordingly. My 1648 grizzly is not a true mud hull but does ok with the 27 MB LT- after adding steelflex it also made the boat drift sideways a little, like an airboat, so I have compensated for that by shifting my body weight a little and slowing down.These motors are definitely not for wimps or whiners- just think how fit and strong your left arm will be after a whole season of this madness! Each hull is different and you'll find the "sweet spot" for placing your gear on board- I found that by relocating the battery up front, this small weight shift helped, it may not be suitable for yours. I think that for your bayou environment and my shallow water/hard bottom marsh, the longtail is a better fit than a shorty.