so the definitive statement is the new bars can fly old kites but new kites shouldn't fly on old bars.
i found this youtube which is supposed to be a demo of why:
https://www.youtube.com/watch?v=Ro-T0E99REc
but i wouldn't say i was massively convinced one way or another. the kite floats at the edge of the window and the release is pulled. it doesn't soften a lot more but i'm not sure it would fly or not and when he walks towards the kite it flags and parks on the beach.
now this doesn't duplicate a constant pull emergency so this is no recommendation in itself but i don't know if you can infer performance from the test. it appears in some ways that the likely result is similar to the switch 2 and switch 3 bar systems which did not really have flagging, they just had large depower by extending the bar throw if you let go (or if you blew out the fixed stopper on the PVC tether) and emergency out was to dump the kite just above the chicken loop with no flagging line.
I still fly some of those Switch 3 kites but they were even more difficult to flag because the front and rear bridles/lines were actually connected so maybe you would get even a little more result with the IDS bar and the 2014 kite even if the bridles have maybe been tuned in anticipation of single line flagging.
Partly i'm trying to decide for myself whether to get a 2014 kite with no bar for the time being and maybe upgrade straight to the 2015 bar when i can afford it -- i.e. when the 2016s come out.
I'm also a little ambivalent about the adjustable bar widths. looks like it might be something to break. I had originally assumed when i heard they were adjustable that the ends slid out of the control bar and extra 6 mm for a long setting. this also gives you that slightly wider bar for leverage as well. Maybe this adjustable thing is a great innovation but i'm wondering what folks who have ridden it think.
thanks,
brian