We’ve been teased with the promise of a soon-to-arrive update for Samsung’s Nexus S 4G on Sprint WiMAX for a few weeks now. It was supposed to land back on July 11, and then we heard July 18 was a possibility. Those both fizzled, but now Sprint’s put out official word that the update will finally get here on Monday, July 25.

This update, system software GRJ90, will supposedly mark the arrival of Android 2.3.5. It will also activate the secure processing component of the NS4G’s NFC transponder, setting it up to be ready for Google Wallet. We knew that update would bring a new 4G settings widget, and supposedly include some tweaks for better WiMAX performance, but didn’t know just how well those changes would translate into real-world performance.

Engadget has been able to test a NS4G with the update installed against one with current software, and noted an immediate improvement in both 4G upload and download speeds. Just what kind of gains you can hope to look forward to will be largely dependent on the state of the WiMAX network in your area, but the site’s testing showed download speed gains in the 20% range.

Source: Engadget