"Are there any negatives to installing either of these pumps?"
Generally a backup sump pump doesn't produce as much volume. Also, any pump that sits for a number of years without being used could be stuck (rare but it happens). We suggest that before each rainy season that you turn on these pumps for a few minutes to make sure all is ok.

"What does the output consist of?"
Output is the amount of water being removed from the sump-pump not including the amount of water being used to operate the pump. The pump uses an equal amount of water input for operation so the actual discharge amount is double the output rating.

For example:
Output rated at	125 gph
Input amount	125 gph
Discharge (total)	250 gph

"How reliable are both of these pumps?"
The battery unit is made by well-known, and long-time-in-business, Little Giant Pump Manufacturing. We have sold many of these units, and have not heard of any problems with them. As most people are aware, batteries generally only last 3-5 years. The better battery that you install, the more energy and reliability you will have, due to the quality of your battery. We recommend that you purchase and install the best battery that you can afford. The water-powered unit is made by Zoeller which is a well-respected company that specializes in pump products.

"Anything else I should know before purchasing these?"
The HOME GUARD comes with a water check valve but in a number of states where you are getting a permit, you must also install a legally approved 3/4" double check valve device when installing water to the HOME GUARD. Because potable water is directly connected to the HOME GUARD (which could have non potable water in it), many codes and municipalities require that an additional, special backflow device be installed. The HOME GUARD does come with a back flow device but many municipalities and codes do not recognize that one as "approved." We recommend that you check with your local building department and, if required, also purchase a 3/4" double check valve assembly from us. We always recommend a double check valve but if you don't need one then we hope that you will at least install a quality 3/4" swing or spring check valve.