If you are looking at the same price range then yes you can compair the arc 4050 to the jl 300/4. If i was gonna compare amps in power i would say put the zapco c2k 2.5 up against the arc. The zapco is much more expensive but its the same power. It depends waht you are comparing. I usally go by a price range and what i can get for that amount of money. Im sure almost every reputable manufacturer worth anything underrates their amps including jl and arc. For this guys purposes he is not runnig horns. Also 2 ohm mids are nice but don't seem to be very common either. Since they are fairly rare it doesn't makes sence to make an amp for them. I agree that some amps are better suited for some jobs than other. If youa re gonna run the sub bridged then i don't think the 30 extra watts is going to make a difference. For this guys system I wouldn't think the 300/4 would be a bad amp. If he was gonna run your setup i would go with another amp. By looking at the stuff in your sig i can tell you really know what your talking about so ill stop