I have owned several pressure washers of various makes over the years (including a Karcher) for cleaning my paved patio and all have been much the same for cleaning effectiveness (and all have failed after a year or so). However, this Karcher K4 Full Control model I have recently purchased from B&Q is by far the most effective. Years of filth which have partly resisted removal in the past have been completely removed by the patio cleaner tool, which speeds up the cleaning process considerably and the power jet tool is equally effective for the small areas like corners which the patio washer misses. OK, it is the most expensive pressure washer I have ever bought at £230, about twice the price of the last pressure washer I bought (which failed after 18 months) but as my patio now literally looks like new I consider it money well spent. If you can afford the price then it is well worth the extra cost and I strongly recommend this product.