NP Saber 7,2

[SteveM]

Hi,
I sail a Hypersonic 111, weigh 75kg. I normally sail with a Gaastra Nitro 5 6,6sqm sail.
I could get a NP Saber 7,2 (2006), for a decent price - my question is, would it allow me to sail in lighter wind (my mate says no, the cambered 6,6 will have more bottom-end grunt.)
We were sailing in 15-18knots, he was on a Fanatic Slalom 120 with 7,6 race sail, and couldn`t shake me off his tail (could be the reason he would discourage me from getting a bigger sail !)
The main reason I`d consider this sail is it fits my current mast (460) & boom (max. 215), so the cost is only the sail, no new hardware needed. I`d prefer a 7,5 but none fit my current boom.

Any thoughts ?