It can be very unnerving to take off and realize that your hydraulic pump is turning on and off repeatedly and that you have no way to stop it. Even if you have a master switch to turn it off, you still have to worry as to whether there is something wrong that is going to keep the gear from extending when you get to the airport? These kinds of "white knuckle" problems are just not necessary.

Add to that the fact that a pressure switch system also requires relays.  Relays that can carry the loads of the hydraulic pump are HEAVY. They are also capable of failing. If you add it up, you have at LEAST 4 elements in a pressure system that can fail and cause you a really bad day.  2 pressure switches, and 2 relays. You still have to have a circuit breaker, and you still have to have a master on/off switch in case one of those things does fail, and you still have to have a selector switch.

I know of one individual who has gone to unbelievable extremes to make his pressure switch system work. When he promotes that system, he doesn’t mention the fact that he has had all kinds of problems with it and spent a great deal of time repairing damage, which was the direct result of the pressure switches. He just carries on about how superior the system is and how backwards and obsolete the 2-switch system is. And then there is the matter of what should be a great deal of embarrassment from causing the airport to be closed so many times due to his gear up landings. But some folks are just not into admitting they are wrong no matter how foolish they look to others. They just blame the problem

With a simple "single pole double throw" selector switch and a simple switching breaker (for on/off) you can eliminate all that complexity and uncertainty and embarrassment.

Think about a typical afternoon in a Glass Goose. You fly out to a lake and land in the water.  You are idling along when you realize that a boat is coming over to look at your beautiful airplane. (They do that a LOT.) Now boaters are not renowned for their intelligence or judgment around airplanes, so this yahoo pulls out in front of you like you have brakes and a reverse gear! (They do that a lot too.) Realizing that you are going to hit this dummy if you don’t do something quick, you kill your engine and reach over and lower your gear to help brake your forward momentum by dragging the gear in the water. Great, it works and you are able to give the guy a piece of your mind while still having an undamaged aircraft. So the guy offers you a beer as a peace offering and then drives off. Now it’s time to go home. Nothing to it, just retract the gear and start the engine and take off, right? Only problem is that when you switch the switch on your super special amalgamated copycat automated pressure switch system, NOTHING HAPPENS.

Here you are in the middle of the lake. The sun is going down. You can see all the boaters loading their boats over at the boat ramp. You stand up and start yelling and waving for someone to come tow you in knowing they can’t hear you that far away anyway. All the while the guy you refused the beer from is telling everyone to stay the hell away from that raving maniac out there in that weird airplane. Oh well, there’s hope. The wind is coming up and it is going to blow you somewhere. Maybe to the most remote part of the lake, but SOMEWHERE. And you’re just sure that the thunder clouds building in the distance aren’t coming your way when your very perturbed spouse reminds you of the weather forecast for severe thunderstorms just after dark, and mumbles something under her breath about someone she doesn’t think is very smart.