Several differences
The Penguin will be noisy eventually, both from impeller noise and from splashing as the water level lowers. Keeping the impellor really clean helps. Flow rate is good, not too much, not too little, IMO (I've had this 330 on a 29 gallona dn on a 105 gallon) When the power goes out, the penguin will always come right back on. During a large water change the siphon will lose its prime but just pouring water in the back will fix that. When the penguin is dirty it overflows into the tank. The biowheel is nice, especially if you need to switch an old one to a new tank, instantly cycled. Cartridges contain carbon, great for crystal clear water but expensive. If you want cheaper cartridges you can buy a clamshell type frame that will hold cut padding for cheaper replacements. If you get the 330, there are internal baskets for extra media like peat or whatever.
The Aquaclears seem to be generally a bit quieter (I only had one for a short time on loan so I cannot say that for sure). Flow rates seem high which means that mechanical filtration is better and biofiltration is a bit less. I've read of some issues with the filter overflowing onto the floor when dirty or overfilled with media. If you use two sponges you can maintain bacteria by alternating cleaning of each sponge, and you can move one sponge to a new tank to help in cycling.
