I ordered a small form factor refurbished PC from TekRefurbs.  It was as expected, but the AC adapter was making a high pitched whine.  I contacted support by email late one evening, asking if it would be possible to replace the AC adapter without shipping the entire thing back (I had already set up the PC).  by the time I checked my email mid morning the next day, they already had a repalcement AC adapter on the way to me!  Fantastic service!So far the PC meets all expectations as well.  Thanks much!