Horsepower claims are only worth the paper their printed on. A better "stake in the ground" is to see how fast each engine turns a specific size and brand of propeller. The more powerful engine will turn it faster.

Weight? The Fuji, being a magneto engine, will be heavier due to flywheel, etc. The DA, ZDZ, 3-W, all those "application specific" R/C engines will be lower weight.

But, watch out for some manufacturers claims about engine weight. Make sure the total weight includes the prop nut, spark plug, ignition system, battery, muffler, mount, etc.

You can find some engines that claim to weigh 2.5 pounds. "Oh, do you actually want this engine to run? Then it'll weigh a bit more."