I disagree and say the opposite.
In a none ABS car If you stamp on the brakes (to hard as an immediate reaction in real life situations) you lock them up then release brake pedal pressure and apply again to stop.
An ABS can do this a thousand times quicker than you with the pressure issue and the apply and release issue which is why you feel a pulsation in the brake pedal,
You also have the added safety of being able to steer around something with heavy braking applied (Like a child running out between a parked cars)
So ABS doesn't just limit the amount of pressure.
Regarding ABS... one of (if not THE) best safety feature ever invented for cars.
People saying 'I'd rather have no ABS, I can stop quicker' are full of BS... I can't think of a race series where teams would decide not to use it if the rules allowed it... F1 is the pinnacle of motorsports, and all the teams would use ABS if it was allowed in the rules.
I'm not sure how average Joe can claim to be better off without it when the best drivers in the World would chose to use it... well, other than bravado
Firstly, I agree that ABS was/is one of the major safety inventions in the auto industry and it is a must have in all road-going cars.
A car will stop in a slighty shorter distance if its wheels are block. When they are fully lock and the car is slidding, the only energies that are still causing that motion are the ones resulting from the inertia coming from the car's speed+its own weight, and will stop when the tyres grip ability equals or exceeds that inertia. Drivability on the other hand under those circumstances is close to zero. When in a non-ABS car you loose the brake when you feel the wheels locking what you are doing is none the less than doing "manually" exactly the same thing that ABS system would do: release pressure applied on brakes, thus reliefing the wheels allowing them to spin again. Obviously, that "system" is much faster doing it than the human.
So, what you both say is not entirely wrong because it'll be your natural tendency (while in a non-ABS car) to relief the pressure on the brake pedal when you feel the wheels locking. And since the system more efficient in doing so, obviously,
under those circumstances, the ABS car will stop in a shorter distance.
However, when I said that the ABS car would always have a longer braking distance than the non-ABS one, I was assuming similar cars, track conditions, and behaviour from the driver. And under those circumstances (in the non-ABS car keeping the brake pedal to floor all the time) I repeat: the non-ABS car will always stop in a shorter distance.
Now this is obviously an abstract situation and in practice, in a real-life situation, in the traffic, there are several other factors to be accounted as other vehicules/people and there, for obvious reasons, you need to keep all the times the ability to steer away for any obstacle during braking - this can only be assured by an ABS system. And it does so because of the pressure relief it would apply on the braking system to prevent wheel block - technically this is what ABS does and how it operates.
As for applying it to the racing, the gain of it wouldn't be getting shorter braking distances but the ability of preventing the braking while turning without the risk of wheel blocking - which, every time it happens under those circumstance, contribute immensly to unbalance the car thus causing the driver to lose time whilst struggling to regaing that balance back.