OK Robbie I will try to give some indication to your questions best I can.
The Edge is my most used kite of recent times in 7,8,10,13 and 19m, so comparisons relate mainly to this kite.
"Did you find you needed to get a bit of speed before the Boost got its power and did the power remain steady as your speed increased or decreased?"
The Boost had good power/grunt at the low end and built constantly as speed increased probably due to its higher AR it did remain steady through out.
"Do you get any power spikes or power changes from an upstroke or down-stroke while signing the kite?"
Found it had steady power on the up stroke but more aggressive pull on the down-stroke didn't feel spikes as such.
"Do you reckon the Boost is a more freeride than the Edge but without it being too freeride like the Infinity/Fatlady type of kites?"
OK not flown the Fatlady or the Infinity so cant judge against these kites but would say the Boost has a better freeride application than the edge, it will turn better and drift better than the Edge IMO (jumping see what EPPO has to say he now has the Boost to test).
"Is the steering reasonably direct or is there any inherent "bridle kite" feel or lack of a better word, spongey?"
Found the steering to be direct but did feel it a little spongey if I aggressively fully sheeted out, this was only momentarily as the kite re-tensions the back lines and this may have been more to do with my lack of time/timing on this kite to be fair.
Hope this helps
