Kevin - I've heard the 4 paddle work better than a 2 paddle but.... I suspect that may be only in certain situations or conditions. As Dennis describes below, the single stage throwers "force" the snow along the auger, and up and out of the shute. In effect, the more you force (drive) the snow into the thrower, the more (better) you force it out.
From the "For what it's worth department, I'm not an engineer, but logically it would seem if you have 4 paddles pushing the snow into the shute, it would provide a more even flow. On the other hand, if I recall how the 4 paddle auger is set up, it's just offset side to side from the way the 2 paddle is set up. So instead of each side of the auger bringing the snow to one center paddle at the same time, IH offset one side of the auger to the other so it would have 4 paddles - actually what might be better called 4 "half" paddles, since the other side of the paddle is open I suppose some of the snow just falls off into the part of the auger connected to the next paddle. Maybe there is an engineer on here that could do some calculations and give us some expected scientific results. If I recall some past discussions someone had found out that IH testing was done using water in a pond. I wonder what that looked like, and how they would actually do that.
From my experience I used a 2 paddle with a 1450 for at least 10 years, and thru all types of snow in CT winters. I never used the thrower until I restored it including complete disassembly, new auger bearings, needle bearings on the chain sprocket, and tear down inspection of the right angle gear box (but the bearings and gears ended up being in great condition). I straightened the auger blades and had some touch up welding done where the auger connects to the paddles. Also, I cleaned and removed all rust before priming and painting with correct IH (CCC) white paint (was not aware of the graphite paint at that time). It always worked perfect when I used it over the 10+ years. Every snow is different and you have to figure out each time exactly how to work it, but always always always run as fast (tractor speed) as you can, at full throttle so the auger is at top speed. Most of the time the snow would throw about 15-20 feet, but the lighter stuff would go about 30, and yes I actually measured the distance a few times due to these same type of discussions. Sometimes the heavier wet snow would only throw about 6 to 10 feet, almost as if it were a water arc it was so wet. If I recall correctly you want to set the shute angle as close to vertical as it will go (just slightly less that full up on the setting). Also, my shute would get blackened from the exhaust so I knew it was getting some heat but I don't recall any issue. I believe the key to best operation is good paint (no rust), full throttle, and as fast as you can push the tractor speed.
Hydro Harry
Old Cubs Never Die