I have been looking into a TPMS system but wonder if anyone has had an issue with the sending units leaking.
My question comes from a bad experience from a more out dated Valve Stem cap that would change color when the PSI was low. That Valve cap was only good when you could bend down and look at the Valve cap (ie: before a ride), if you saw a Red indicator your tire was low. My issue was the Cap them selves would leak over time.

I don't have a phone that will monitor the system thru Blue Tooth and I really don't need any features other than an audible alarm if tire PSI drops.