I bought a Met 3 weeks ago and had a display issue. I spoke with Chas regarding the warranty and he confirmed it is general 60 days (Longer for display) however he said that they do consider warranty replacements for several months. Given that the defective part was a display, the RMS needed to be processed by my distributor. I have purchased 5 NIB Sterns and will say that I have been fortunate to only have this one issue requiring an RMA. I have had a couple of minor mechanical issues which I worked out myself but with EXCELLENT support from Stern even a year or more after purchase. If I asked him to, he would have sent out any of the inexpensive parts but it was not necessary.
In summary, I feel confident that you could buy a NIB Stern and get warranty parts replacement for at up to 6 months. They seem very fair!