I have the "other", most common type (they go by different names). It's like $129 and has two screw on sensors and a wireless receiver with a display.
It works reasonable well. On my last trip I found that the readings were all over the place, and I'm thinking it was a combination of high altitude and maybe weak sensor batteries.
It alerts you to dangerous situations by beeping if the pressure drops too fast or above/below a preset threshold. And you can hear it, but not loudly. It also vibrates, and is meant to go on a keychain. I mounted it with velcro to a spot on the dash. I can see and read it fine, except at night when you have to tap a button to see the backlight.
I like it because in my opinion it works better than something costing $130.
I read the reviews on the orange, and the comments were pretty harsh about the customer service. Some guys couldn't get a sensor to work no matter what, and there was no support, little or no communication, nothing from the company. And I wasn't sure if it would mount properly on the back wheel where the valve stem is offset from center. And I don't know if you can change the batteries in the sensors, similar to the BMW sensors (you have to buy a sensor when the battery dies).
I've used my system off road, fully submerged, high frequency bouncing on a washboarded road, you name it.
Mounting the display was tricky with velcro, but I managed to do it while still allowing access to the battery door.