I've heard you notice quite a lot of difference with a bluefin on a 197
I've not had it done, but know a bluefin map will be a generic map. I.e. Not tailored to your car.
This isn't a bad thing, especially if your car is standard, or near standard. You won't get any power (any noticeable power) due to the engine being naturally aspirated, but you may notice an improvement in drivability; less kangarooing, no flat spot, smoother power delivery etc etc.
But make sure you're not paying over the odds.
For reference, you can get an rstuner for circa £120 if I remember right, pay £40 to have it unlocked and then £xx for a generic map to load to your car.
You can then sell the rs tuner on for £120 to recoup some costs.
Have a search for those on here.
If your car isn't standard; cams, inlets, exhausts, plenums etc, you'll want to look into a custom map by the likes of RSTuning or efi parts.