We may have coaxed you into too high a tension... I would ask how much the blade deflects when you push it laterally BUT it is so subjective that is is almost worthless unless you have to really push hard to get 1/4" or so of deflection then it is definitely to tight. I setup a 10-325 for a friend of mine with a standard carbon Lenox flexback 3/4" blade (must say not a fan of the guides, though quite frankly there aren't many saws I really like the stock guides on) and I didn't feel it was too much trouble to crank the tension on properly.
Tension is such a feel thing, even if the saw scales were accurate for one thickness of band it wouldn't be for a thicker or thinner band, nor could it be accurate for carbon and bimetal or carbide tipped blades. Unless and until someone brings a tension meter to market designed for the 0-30,000 PSI range it still remains a matter of gut and feel.