I have two 180's and use the jebao RW range. There's four in the range, the RW4, RW8, RW15 and the RW20. I started off with the RW20 in one of them and was astonished how powerful it was on top speed (the full range is variable speed which is brilliant). This thing shifts 20000 litres of water an hour on its top speed and literally makes my 180 look like a whirlpool. I run it on its lowest setting. So when I decided to get one for my other 180 I dialled it right back and got the RW4. The RW4 is OK, I run it on its top speed to achieve the movement I like though in all honesty I should have gone RW8 and then used the variable speed adjuster on it to tweak it. I have mine on timers too so I only have them on a few hours each day.
I find the RW's to be brilliant but I haven't used any other brand, which there are many, some a lot cheaper than the RW's, some more expensive than the RW's. So I can only give you a biased opinion really on my own usage.
One thing's for sure though, powerheads are brilliant for moving water. They get rid of dead spots, they help shift waste so it goes into your filtration system instead of sitting on the bottom of your tank and my fish love the movement (not all types of fish like turbulence though).