RE: Board Selection - Totally Confused
Yes, the Motion is heavy, so why not build a beach cart to transport your board from the car to the water?
Perhaps part of the reason your board feels like a "dead whale" is because you don't have the wind speed and sail size to gt the Motion to perform.
You do @ 110 Kg.) have a lot of drag, but you don't currently have very much power to overcome all that drag.
Get the bigger rig an I think you will see that with enough power, the Motion will "get into motion" and the drag factor will fade away.
Perhaps the reason you can't get your Motion to turn is the way in which you are trying to make it turn.
Do you "rail" your board going into your tacks and jibes?
Do you move your weight slightly forward and back to get your board to sail more upwind or downwind?
170 liters would certainly be enough volume to float you, that's not the problem here.
Your skill level and conditions simply don't support getting a smaller board.
You may have great "slogging" skills, but with < 14 knots of wind, at your size, with your 6.3 m2 rig there's very little possibility for you to progress to the stage where you can make a < 170 liter board work.
As soon as you get enough power to plane, you will be learning a whole new set of skills.
As I said, when you get a rig that will have you hooked in to your harness, fully back in the footstraps, with the rig supporting your weight and the board planing nicely (and fast!) THEN you can start looking for a smaller lighter board.
Perhaps it would be good for you to take a vacation in some warm and windy place as then you could rent gear and try out a lot of different boards, get some accellerated lessons and learn in a few days what it's going to take years for you to learn in your home conditions.
The bottom line is that a < 170 liter board simply won't work for a guy your size in < 14 knots.
Hope this helps,