For a bit more info on my choice, I should add that I am tight as a tick on spending money on equipment. I have to see a definite advantage before I go for the higher cost item.
In the case of powerheads, I went through several big box store brand cheap ones before deciding to "invest" in four Maxi-jets (1 400, 2 1200s). After trying them for a while, I had trouble with them all using the impeller. The design to stop it and make it turn the correct way was not good and it got so stopping them for water changes or cleaning was a job to get them to start in the correct direction. I switched to using them as circulation pumps but then they were really noisy as I could never find a way to mount them that did not vibrate through the tank. My best shot was mounting it to a DIY concrete mount to set on the sand at the bottom without touching anything else. That worked to quiet it but was not a fun time when it came time to clean the impeller.
Overall getting the Koralia has convinced me that I should consider paying more for some things. The flow is plenty in my 125 for what I want there and the magnet on suction cup is the first mount which really seems to work and hold it where I put it. The Maxi has a three suction cup mount but it always found a way to tip so the water started blowing the sand around.