Pros: Great water flow for size and run longer dirty. Quiet.
Cons: Run a little warm, limited accessories with pump.
I have been using a Mag 7 pump in my aquarium for almost a year now and it is by far the best pump I have. The amount of water that it pushes for the power it consumes is difficult to beat.
I thoroughly researched pumps long before purchasing my Mag 7 and encountered a lot of fellow aquarists who swore by the quality and durability of these pumps. I even talked to one aquarist who dropped his pump from about 4 feet high onto concrete and he plugged it in fearing the worst and it kept right on working. Not that I would recommend doing that, or that would be the typical result of such an accident, but just what I heard :)
These pumps come in a range of sizes and power for pushing water. They push anywhere from 65 to 3600 gallons of water per hour for a cost of 5 to 360 Watts. It is too difficult to do a table here, but a lot of details are found at one of my favorite online stores:
Durable pumps with quality construction. I find their impeller design is much better than similarly priced pumps.
I am sometimes lazy about my aquarium maintenance and the mag7 pump has never stopped working when it is dirty. I have several other pumps(mostly Rios) that will stop working when too dirty.
My mag 7 is very quiet and several others have reported that the larger pumps are still quiet, but not as quiet as some other pumps(notably the aptly named quiet one pumps)
Once you get up to the Mag 2 pump they can be used externally, that is they don't have to sit in the water. Given the heat production of these pumps, that is a good thing.
Due to the impeller design used in these pumps they are not able to pull water up to them from below. So the pump must sit below the water line of whatever application it is being used in or it will not pump water.
The power consumption is respectable, but these pumps seem to get hotter than some other lines. If you are setting up an aquarium in a hot region, such as my home state of Texas, then the heat could be a drawback. This can be minimized by plumbing the pump externally so that it sits outside the water and most of the heat will be dissipated into the air.
If you are only using one or two pumps I don't see this as a problem, but if you use several, then you might not want too many mag pumps. Conversely if you live in a cold climate, you will want the pumps in the water to reduce the amount of work your heater will need to do.
Once you get to the Mag 2 pump and higher there is very little to no mounting equipment included with the pump. You need to figure out ways to do this yourself. This can be a problem as these powerful pumps can "hum" if they are not securely fastened to a surface. There are mounting holes included on the pump, just nothing to put in them. Hopefully the company will fix this in the future.
Looking for a pump for an outdoor pond or an aquarium? You won't do much better than the Mag-Drive series of pumps, especially at their reasonable price.
Just be ready to figure out a way to mount the pump to a surface solidly as the mounting equipment is not included. Then sit back and enjoy your pond or aquarium. Just don't be TOO lazy and clean it once in a while :)
My Other Aquarium Related Reviews:
Salifert pH test kit
Salifert KH/Alkalinity Test Kit
Salifert Calcium Test Kit
Salifert Magnesium Test Kit
Salifert Phosphate Test Kit
Aquarium Pharmaceuticals FasTesT pH Test Kit
Aquarium Pharmaceuticals FasTesT Ammonia-Nitrogen Test Kit
Aquarium Pharmaceuticals FasTesT Nitrite-Nitrogen Test Kit
Aquarium Pharmaceuticals FasTesT Ammonia, Nitrite, Nitrate and pH Test Kit also called the Multi-Master Test Kit now.
Aquarium Pharmaceuticals FasTesT Nitrate-Nitrogen Test Kit
Aquarium Systems SeaTesT Hydrometer
Hagen AquaClear Power Head 201
Rena Air Aquarium Air Pumps
CPR Aquatic Cyclone Bak-Pak 2R
Aquarium Systems SeaClone Protein Skimmer SCPS-100
Aquarium Supply Stores:
Marine Depot Aquarium Supplies
Drs. Foster & Smith Online Store
All-Glass Standard Size Aquariums
All-Glass Large Size Aquariums
My Aquarium Advice:
The top 10 things you NEED to start a saltwater aquarium