Angel Tuning remapped my 156 2.4JTD 10v (150hp version) some years ago, and I can tell you it felt as though a different engine with much more pulling power had just been fitted. Not sure now what map used, I think it was Nigel who came out, but could be wrong here.
The Mad Map! was mentioned as it could lead to gearbox failure with the increased torque!
At the time my car had done 99K, and some clutch slip was noticed after the re-map (no surprise there with 99k milage on the same clutch). So I learnt to avoid accelerating away using high gears with low revs and promised myself I would get the clutch replaced. And after buying a GQV things kind of slipped getting this done.
Also my MPG went up, that I did not expect.
Perhaps due to, being able with care to keep in higher gears without so many changes!
Thats also why I prefer the 5 speed gearbox in my version.
So after doing nearly 80K since the remap on the original clutch (still), now with 177K miles the peddle travel is quite high now, replacement sometime this year due to normal wear, not my lead foot!
Without any doubt £ for £ the diesel remap was the best I have ever spent on increasing an engines performance, and Angel Tuning have lots of Alfa JTD experience too.