Both have pros and cons, the 6101 the driver is now in the pump, it is sealed now so it cannot be damaged by water. The power supply is what is used on laptop computers, you can buy a replacement virtually anywhere as a result. Supposedly the new electronics are more reliable and use less power.
The old design with a seperate driver will be cheaper to repair as the driver and motor seperately will cost less than the new motor with built in driver. The old transformer I think will prove more reliable. Laptop power supplys typically last only a few years, we chose the coolest running oversized power supplys we could fine but I still think they will last 4-5 years in most cases. The old copper coil was basically forever.
We changed the design for two reasons, we see a lot of water damaged drivers and customers wanted less hardware to deal with. In addition the laptop power supply greatly reduces the weight of the box, a 6100 weighed 7lbs, a 6101 weighs about 4.5lbs. This minimized transport costs and shipping damage from stacked heavy boxes.
