I'm making plans for a new 20-gal and I just saw some nice Cascade filters in my local petstore. Does anyone have any experience with them?

One of the reasons they interest me is the way that the water comes out, so it doesn't create a washing machine effect in my tank (which I've had problems before with some other filters). I really don't want my future goldies to be knocked into the walls.

Some opinions about the actual filtration system would be appreciated as well. I'm only exprienced with marineland filters which use the floss/carbon cartridges.

I'm guessing you are talking about the HOB filters, not the internal ones?
I have an internal one running in my goldfish tank and I'm quite pleased with it. The first one broke.. but that was a one off I think.
I'd probably recommend that brand of filter if you where looking for something cheap but good. If you have the money though go for something a bit better quality.

Yeah, I've only seen HOB cascade filters, but I have seen internals of another brand. I didn't think they'd be suitable with goldfish though. They looked like you just stuck them inside the tank... Kind of like the updated filter in Little Nemo with the lazer light!

Externals are better with goldfish (apparently! since I've only ever used internal.. I've never seen a HOB for sale in the UK ) but the internals work just fine on smaller tanks. I would prefer an external because I think they are a little less 'flowy' and push the fish about less.. and they dont clogg as easy.. but I'm scared of it leaking or catching fire!

Scary!

I prefer Whisper filters, but if you arevery interested in buying the Cascade, I ask you to go to the website below to read about how it performs in reality.
http://www.cloudytanks.com/reviews/filters/cascade.htm

Thanks for the link fishie! It was really informative. According to the link I may need to go several sizes larger than I thought...

I have one. Its ok I guess. Just dont like the way you have to attach the motor. I am always worried it will fall off and then Ill have water everwhere. I don't think Ill buy anouther one.
I like the whispers better. I dont like the internals filters at all they just dont do enough gph for a goldfish tank and they take up tank space.
I have two Whispers that do 300gph each on my 75g not enough gph but pretty close I plan to try to fit on a third one this Christmas.

IMHO, you should try a Whisper. They are quiet, reliable, and even keep your gravel clean with proper placement of the WonderTube (intake tube). They have fairly high flow rates, too. The internal Whispers work just as good, but if you put that in there, you have a big black box in your aquarium that your goldies can get stuck behind because of their large bodies.

Thanks everyone for your sound advice!

I might stick with other brands that I'm more familiar with. Looks like the Cascade may need a couple more improvements before I make the investment.