subcamper,
I have had that pressure washer for about a year now....used it just again yesterday. Didn't get it at Lowes (didn't even know Lowes sold it), but at a small landscape maintenance supplier who also does repair work. So far, I have had no problems with it. My understanding at the time was that washers with horizontally mounted pumps (like this one) are less prone to failure than those with vertically mounted pumps typical on some of the lower priced units (like those at Costco). If it was me, I would not get the extended warrantee.
Good luck and happy washing,
Steve