No track days and you are missing the point. I never said I need better braking, or that the brakes can't cope. I want better braking and I want less pedal effort, I want more response. Wooden dull and adequate works, but is not my thing.
I also want to recode the steering assist, it's too stiff. A jag, i can whip round a hairpin with my little finger, ditto parallel park. Does that mean I'm driving too fast and can't turn the wheel? No. It's all about the feel, effort and the reserves, I drive mainly up to the limit and within the standard van's capabilities. Yes I have done track days, I have a full clean (many years) bike and car license and I have a load of performance vehicles to test drive on a regular basis (I own a garage) and my other daily driver is a 5.0 AMG 330hp. The brakes on that are not good either. The brakes on my superb, my croma and my partners Meriva are all superb, I like the feeling of only needing to breathe on the pedal and getting a strong g-force pull which pulls you up quicker than you need to, so you have to back off the brakes. It's very confidence inspiring a) always stopping quicker than you though you might and b) being a long way away from the point of lock up, so that in an emergency eye popping levels of braking can be pulled out of the bag c) not having to beat up the controls, just breathe on them to make for an effortless drive.
The existing brakes are okay, but the pedal is heavy and they don't have much bite, when braking to a roundabout I will press the pedal what I think it hard enough but near to stopping point the braking hasn't met expectations and I have to press harder with a slight 'is this going to stop in time' feel. It's not that much about braking hard, more about gentle pressure generating lively and confidence inspiring braking.
But this is just personal, if you like braking with a wooden feel and a noticeably heavier pedal and lower g force per lb pressure than other similar vehicles, then leave them stock. It just doesn't inspire me. Being as a workshop we refurbish and powder coat brakes for RS, Porche etc if I'm going to do them I might as well showcase the brakes a bit - but if I didn't do it for a living I would probably be happy enough just with some decent pads. I prefer black diamond for my own cars road use, excellent bite even from cold. Hope that explains!
Uhm.... Are you doing track days or something? Maybe carrying larger loads? To sound like an old git if you need bigger brakes on a standard car on normal roads then you drive at least a little too dangerously and I fear for you, your passengers and those you might collide with.