I haven't tried it. One reason I love the Insight is I don't
have to pulse & glide to get ridiculous fuel economy at ~80 km/h / 50 mph cruising speed.
If I had to guess though, I'd predict lean burn would still beat 60-90-60 P&G. Others have tried this, no doubt.
EDIT: I did lots of P&G during the
2012 SMCC Montreal fuel economy rally, but only because the course wasn't lean-burn friendly. (Lots of hills/turns/changing speeds, with tight time deadlines on each section.) It was enough to place well in the competition, but it was the worst "fill-up" I've had in the car since I got it.