I had a similar problem on my Roadster when I bought it which was surprising given the Tarox 6 pot conversion a previous owner had fitted.
So I spoke to Tarox and the tech man explained that some pads can be prone to glazing on light cars which need relatively little pressure to slow the them down.
His tip was to "de-glaze" the pads by rubbing the faces together in very hot water with washing up liquid.
I couldn't believe the amount of muck that came off the pads and the braking surface looked like new after I had finished. (Rinse them with clean hot water when you've finished).
I also cleaned the callipers and discs with brake cleaner and applied fresh Ceratec grease before re-fitting.
The transformation was amazing with much better bite and very progressive braking all the way to lock up.
I've done 3000 miles since the cleaning and I can just start to feel them going off a bit so I will do this as part of my annual main service in future.
Might be worth a try for you before you spend money on upgrades.
Interesting that Bob, may give it a try
