For anyone following along, Geo Robson was the furthest along on powered wingsuit flight. He had done aerodynamics calculations based on the V3 that showed longitudinal instability in the powered flight modes. You can read more here:
The take away, is that without vectored thrust, it may not be possible to maintain stable flight, regardless of the thrust you throw down. Geo suggested active thrust vectoring to make the aerodynamics work. I haven't seen anyone do any mathematically vigourous work since he went in, but I expect naive applications of thrust to have the same issues in a modern suit as he saw in the V3.
Wingsuit and Electric Jetpack
in Wing Suit Flying
http://raffaello.name/wp-content/uploads/2013/09/AIAA-237998-291.pdf
The take away, is that without vectored thrust, it may not be possible to maintain stable flight, regardless of the thrust you throw down. Geo suggested active thrust vectoring to make the aerodynamics work. I haven't seen anyone do any mathematically vigourous work since he went in, but I expect naive applications of thrust to have the same issues in a modern suit as he saw in the V3.