How Do Pilot Exalto's Affect MPG?

After doing an enormous amount of reading here about tire recommendations, I'm really leaning towards
the Pilot Exalto. It seems like a big upgrade in traction and comfort (quietness). But for me maintaining MPG is equally important. The comments from forum users here seem to conflict a little: some say they've seen a slight decrease in MPG, others say they've seen a big increase.

I'd really like to hear from Pilot Exalto owners who have had the tires for awhile (beyond 'break-in' period):
- what's been the change in MPG?
- do you feel that the tire's rolling resistance is as low as the Integrities - i.e. is it as easy to get into the 'no arrows' mode?

Any insight would be greatly appreciated.

Stevejm