Hi Nick. I don't know the Futura, but I did have its predecessor the Carve 145, and I actually had a Lightning 9.4 for that too. I now have a formula 159 (a little less maxed yhan the newest designs) and I sail it with a Lightning 10.3.
Simply said if you use some directly comparable parametres it will be like this:
Early planing: definitely formula (the 144/9.4 is no slough though). The formula will feel powerfull and point earlier than futura. In marginal conditions this means a lot. If you mostly sail in + 10 knots it may mean less.
Pointing and downwind: DEFINITELY in favour of the formula.
Reaching speed: well powered: equal, max powered: maybe a little in favour of the Furura (but formula is surprisingly fast)
Jibes: DEFINITELY in favour of the Futura (basically formula jibes horrible)
Manouvres and looseness: Futura is way better.
Cruising: formula. The ability to point anf go low just brings you a lot around.
The formula will feel a lot harder to sail until you get used to it. Modern short formula designs are actually quite loose and they bring a lot of time on the water.
It's a very personal thing.
I liked my Carve 145, but in my spot the Formula gave me something like 40% more planing time (almost planing days became full planing days)