Yeh I reckon if the wind is low most kites (haven't flown Fuels) are like trying to do circle work in a double decker bus... My old 2003 15.5m Flow is ok for what it is (old, big and slow) but it is a put the indicators on and muscle the bugger (heavy back line stearing) into a turn.

Better than sittin on the beach though

I would have thought you would get a slightly better response from your original (further back) connections. With a big boy like a 17m you are only ever going to be out in low-ish winds so stick to the rear connectors for my 2c.
I think it is a simple case of leverage... Hey i am a simple guy so even i can thunk that thru. The wider the points the more leverage... well that's my crackpot theory for the day.
Geez 10-12kts is frustrating!! Just enough to convince yourself that it is more like 13-15kts and get out there...
Luff~~~~DOH!! Luff~~~~DOH!! Luff~~~~DOH!!
Bugger pack it in... no wait it's picking up??
Luff~~~~DOH!! Luff~~~~DOH!! Luff~~~~DOH!!