I got a custom map on mine, wasn’t significantly more expensive than a bluefin and was tweaked for the car’s other mods and, er, general creakiness. Though, the price was reduced as they had a baseline map for the model to work from, I think a totally new map would have been more expensive.
End result- better “feel”, the car was very wooly down low before. Fuel economy was a little improved, though realistically the running cost saving will take years to balance the cost of the map. Power- can’t say what was from the map and what was from the other tweaks, and what was both, but it drove away faster than it drove in.
Worth it? I think so, but I like driving. I don’t think it’d be worth it just for the economy boost unless you’re doing high miles, for me it’s just a couple of mpg. Car is on 105000 miles, rattles like it’s full of rocks, on original clutch and DMF (probably not for much longer!) and is none the worse for it all.
Only downside is the cost, er, and the fact that having it drive nicer means I use the right foot more.