You and your tremendous arsenal, ataxian. It's a wonder you find yourself on the forums instead of knocked out on the couch most afternoons.
They were too weak for me as well. If you want to do it right, remember that you have to balance everything out: how long and hard you're drawing to how hot and quick the wire is heating up. So if you have a hotter wire, you'll need to draw at a different rate of suction, and for longer. The trick I did with running 2.4ohm that high is drawing a little faster than you would on 3.7v. You "pulse" the button, meaning you press it multiple times, but never for 3 seconds. I do about a half to a full second button press, then continue drawing for 2-3 seconds without, then repeat until the last hit where, after releasing the button the final time, I draw for an additional 5-10 seconds (no button) to cool down the cart. You get disgustingly fat hits and the flavor isn't so compromised
Also, I'd follow OF's advice, pal. If you already have a Hercules, use it the ways everyone here says they work. They already have a known problem, adding to that list will only give you the level of frustration I am currently enjoying, waiting for the new Hercules to be complete. It is yours to use as you please. Just hoping you don't do something you'll regret.
Lastly, the minimum range is, I believe, lower. That's why people favor 2.4ohm at 3.7v. They last way longer as they're the least volatile. The 5ohm at 7.4v is a little more than double that power, so you might factor around half of a 2.4's lifetime for a 5. Then again it's all about how you treat your carts. If you're feeding them the optimal oil, never overheating them, and generally maintaining them well, you should see a lot of life out of both carts.