Diameter(2) + Pitch = load factor.

22-10 ----------- (22x2) + 10 = 54

24-8 ------------ (24x2) + 8 = 56

18-10 ---------- (18x2) + 10 = 46

Do all 22-10 props load the engine the same amount? No. Same load factor, but 300RPM or even 500RPM difference. Do all props that turn the same RPM, regardless of load factor, pull the same? No.

If you want to know which prop performs the best on your particular airplane with your brand XYZ engine--then spend $500 on props and fly the plane on about 15 different brands.

I spent close to $800 on props last season. Now I know what brands I like and what brands I won't buy again. The load factor makes no difference. The pitch, diameter and thrust it puts out while moving dynamically through the air is what makes the difference. The RPM on the ground is an "okay" indication of RPM, but doesn't tell you squat about how it will pull in the air.

Perfect example:
APC 22-10 turns a lot of RPM and makes a bunch of noise--doesn't pull for squat. Unloads too much and rips the tips. Wasted energy.
Bambula 22-10 loads the engine too much and turns very low RPM. Doesn't pull worth squat because it doesn't unload in the air.
NX 22-10 turns respectable numbers on the ground. Pulls very well in the air. Excellent thrust and vertical performance. Doesn't rip the tips.
MSC 22-10 turns good numbers. Pulls very well in the air. Excellent thrust and downline braking. Doesn't rip the tips.
Pro Zinger 22-10 turns "okay" numbers and looks good on the ground. Pulls horribly in the air and rips the tips. Vertical performance is very poor.

You just have to buy a bunch of different props and see how they perform on your airplane. The NX 22-10 might totally suck on your 28% Edge 540, but you might love it on the 27% Extra 300L. The MSC 23-8 might be the cats meow on your 30% Yak and it might suck on the 35% Pitts. Different airplane--different prop.