Infusion will give you a far greater laminate compression than hand which has none or regular vacuum bagging. This insures about a 70% glass to resin ratio.
Infused boats are typically 30% lighter and 40% stiffer than there hand laminated counterpart. And 25% lighter and 30% stiffer than vacuum bagged.
Also consider that hand and vaccum laminations require CSM between all layers, with infusion there is none. But also consider that stiffness is directly related to the laminate thickness, because the vacuum bag compacts the laminate stack ( I use 30+ inches of mercury ). An infused laminate will only be roughly half as thick as a conventional laminate of the same material. Since stiffness is a function of the square of the thickness, an infused laminate ( coreless ) will only be 1/4 as stiff, though tensile and flexural strength will be higher.
As such provisions must be made to regain this lost stiffness, which is simple, step up the core thickness. For example 1/2 to 5/8.
Which brings me to balsa, I would never ever use the stuff inless it was installed with either vacuum bagging or infusion. It must have total contact and bond with the hull, any voids are a place for condensation... and then rot. Balsa installed correctly will not rot, you might get area rot, but water cannot travel latteraly through end grain balsa due to it's vein structure. Also, it should only be used with vinyl or epoxy as poly is not water proof.
Bottom line is, infusion done correctly is the best method of boat building, and with the way the EPA is headed probably the future for everyone ( this is a good thing ), vacuum bagging is worth every penny, and so is kevlar.....