On 2013 Jan 17 I installed a pair of 'tire savers'. On 2013 May 19 a
goathead thorn punctured my rear tube. I had traveled 2,180 miles
without punctures. The rear tire had 2 goathead thorns embedded in
it, a tire liner had 1: the one that punctured the tube. I use 700x25
In the previous 22,000 miles I had 47 tube punctures (total for both
front and rear).
I bought my tire savers from the chain-l.com guy. Another fellow on
this forum sells his own version. I have no reason to believe that
one model is better than another: they're simple.