Front brakes 2 vs 4 piston calipers

I have a 2400 pound mid engine car that I will be building new spindles for. Car came with RBP 2 inch hollow brakes 9 inch rotor and 2 piston calipers. For a 2400 pound car would I notice the upgrade to 10.5 or 11 inch rotor and 4 piston calipers?

Sorry should have noted the front tires are 10.75 by 15 razorbacks.

I have a similar size vehicle and did the upgrade you describe. The 2 piston brakes worked fine but were underwhelming. Upgraded to the 4 piston and stopping power felt night and day. I lead most the time and really love the immediate front locking up when grabbing brake pedal. I have a single master cylinder for front and rear brakes so it's biased to the front and I can't adjust it but I don't think I would.

In my opinion it's a worthy upgrade and I would do it again.

Thank you. I lead allot as well and every now and then those brakes come in handy.