Thanks for the comprehensive review! I do agree with Howard though, too many negatives for my liking. My TST 507 color display shows the pressure and temperature for each tire as the positions cycle through, instantly jumping to flash any position that's outside the set parameters with an audible alarm. The easily replaced batteries cost less than $1 per sensor, and the display has real buttons.
In your situation, since you can buy sensors for $15, I'd suggest keeping a spare or two on hand in case of a failure rather than risk running a steer tire unprotected. A steer tire blowout is much more likely to put you in a ditch or the next lane than a drive tire blowout.