I purchased a Roll'n'Lock cover from them. Was a poor experience and I would not purchase from them again if I can avoid it. Site said it would arrive in a week, took over a month. Zero communication from them after taking the money. I actually got a survey to fill out about how I liked...
Like others, I purchased an extended warrantee. I got mine from Flood, did not see a material difference between Flood or Grainger. For my 24 PB I got the 10 / 100,000 as I generally keep my vehicles for a long time (last Ram was 14 years).
This is probably the first thing I have ever purchased...