but this product claims that it will make it more fuel efficient. fingers crossed for OP's verdict on this after he observes the mileage. Fear of the dark is that it will consume more fuel after ecu got chipped. But if it consumes less fuel than before coupled with increased response that what else we want.
I will not call the Gli as underpowered as I have took it to PAF base kalabagh (Nathyagali) with full load. It climbed without any prob BUT yes Gli is sluggish in terms of initial acceleration/pick. I even installed Iridium plugs for that which just improved it a little.
I have saved some amount (more or less the same as OP's stated about the charges of this device) for buying a good branded head unit but I will drop that idea n buy this thing after observing such like feed-backs but like I mentioned before the power should not come at the cost of economy.