I don't think Sigur Ros is the right comparison. Sigur Ros to me are slower, ethereal and haunting. Your mate's stuff is too upbeat. There are elements of individual Sigur Ros tunes, yes, but to describe him as similar gives the wrong impression.
Having said that, I enjoyed the three tracks and would be happy to hear what else he can do in the future!
yeah I couldnt actually think of any bands to compare it to as im a bit out of the loop of that kind of music, im pretty sure ther are other artists similar to it but I just cant think of the names