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The doc says you may see better performance.
Indeed you may, but the doc also notes "Do not use this command unless you clearly understand why you want to change the default value.".
The two common situations where there's possible benefit to increasing the device's TCP receive window are: to allow faster FTP/RCP downloads to the device or to support quicker BGP bulk transfers. The former is limited by write speed to flash and the latter might be unusual to need > 64 KB for BDP.
Also, BTW, if you do find a need to work with scaled TCP receive windows on a Cisco device, you probably also should enable (optional) SACK.
