Those only tell you the approx pressure while you are standing there looking at them. You NEED a good TPMS that reports to you in real-time. You need to know when you have a problem [slow leak] before it becomes a much bigger problem [blowout].
I have used the TST 507 RV system for about two years and it has performed perfectly. I've had 4 blowouts and 2 slow leaks and each time the monitor let me know immediately. Wouldn't even think about leaving home without it.
You get what you pay for!! It will pay for itself over time. JMHO
2013 Silverado 2500 HD Duramax/Allison Tuned
Aviator Wright Flyer #1919
"First In, Last Out". 11B4Y
DAV, MOPH, VFW, 5/7 Cav,1/8 Cav Assoc.
11th ABN Pathfinder Co. N7MIP