I have had a Doran 360 unit for about 2 1/2 years. I first bought a Pressure Pro, but couldn't find a place to mount the monitor. My dashboard doesn't like suction cups and Velcro doesn't stick to it well enough to keep the monitor steady. There's no effective place in the dashboard either. So I returned it to Doran and exchanged for their model which at the time had better mounting options.
I used the 3 suction cups on the windshield. They are bulletproof—it has never budged. It's kind of a stretch to reach it while driving.
I think they now claim the batteries in the sensors last 8 years. I remove them after a trip thinking the sensor is no longer sending a signal and therefore the batteries will last longer.
The locking part is the same as described in a previous post. The allen screws are tricky to get locked on and not jammed in so far they won't come out. The end of the allen wrench is very small and can round enough to not be able to take the screw out, but you do get a couple with the unit. Usually you can just screw the whole lock off with the sensor anyway without loosening the screws. This past summer the inside of the locking screws got filled with road tar and I couldn't get the stuff dissolved, so had to get new locks.
Last week, one sensor started acting crazy, seemingly not sending a signal all the time. Then the monitor started giving crazy readings. I will reprogram it ands hope it works next year.
When I had Marathons, I had to keep adding air every few days, so removing the locks and sensors was a pain. With better tires, they don't lose air.
I am very glad we got the TPMS as it probably prevents damage to the trailer if a tire blows. Maybe better tires are also a solution to that. It also allows me to check tire pressure every morning and during the day without going around to each tire with a gauge—easier and quicker. The TPMS reads 3 lbs. differently from a hand tire gauge, and I tend to believe the tire gauge more, so I just take that into account.
I am hoping I just have to reprogram it since software sometimes acts up after a while, and all will be well.