I grabbed a BDX tuner from Unleashed in November when SCT had the rebate, Torrie included 2 tunes.
I only wanted a 93 performance so since it's winter here up north I opted for an 87 economy tune as well.
With the economy tune the biggest change I saw was the car now shifted early, like really early. It would shift into 5th before 40, sometimes I get a nasty drive train
growl when it shifts into 6th before 50 mph. It takes a little getting used to it and I try to accelerate quicker to avoid the growl.
On the plus side, during the winter I usually see high 23 low 24 MPG, I'm calculating the tanks at 26 which is what I normally see in the summer.
This is with 2 remote starts/day at 5 minutes each.
I drive about 90% highway so if I keep using the economy tune I'm expecting close to 30 mpg's next summer.
But since 93 octane is around $2/gallon, I couldn't resist, I loaded the 93 tune a few weeks ago and haven't looked back.
Way too much fun/$ to run the economy tune.