Microsoft's update has added some much-needed horsepower
The "standard" pentium offering is a very, very small speed bump a 1.7ghz Kaby Lake process vs 1.6ghz. It was a moderately old design when the Go 1 was released, it's a very elderly processor now, and one which is noticeably slow even when being used for general web browsing.
All they've offered is the opportunity to spend an extra 90 quid (Only on the high end 128gb model) on a processor which isn't crippled by disabled turbo.
The surface go is a lovely machine, but £629 is an awful lot to spend on a machine which is only going to have tolerable performance.