Cave in and bought this model from Brickworks last month. Got the parts and instructions yesterday and built it in about 3.5 hours last night. Kit has 540 bricks total and assembles in 169 steps.
Instructions with super clear for the head and torso, but LDD started giving me crazy instructions for the arms and legs (bricks were not in order). Still managed to build the whole thing, but that part was a bit annoying.
The end result is beautiful imo (as far as Lego customs are concerned). Sculpt looks great, transformation is interesting (borrows a bit from MP-04 Convoy or Classics DLX Prime with how the front wheels fold in), headsculpt is very well done. Without using glue, it's almost as playable as a real toy.
It's expensive ($175), but you get all the parts and the engineering has been figured out for you. I've added some personal touches, like the side mirrors, the matrix, I've redesigned a bit the upper arms (to hide the shoulder joints), the back (for better clearance) and the feet. Changed the color of the eyes (from greenish to blue) and the front lights (from greenish to clear) and added red brake lights to the feet too.
Building Megatron tonight or tomorrow (700+ parts)!