1. Range. The G300NH has much better range than the E1000.

2. Bandwidth. Just because you are in range, that doesn't mean you'll get full bandwidth. Even at shorter ranges, the Buffalo will probably have higher bandwidth than the E1000.

3. Gigabit switch. The G300NH has a gigabit switch, bu the E1000 is just fast ethernet. You'll get faster local network file transfers if your computers have gigabit network cards.