Well valsport says they're light but they're 305g's and light to me is the vapor at about 180g although the legends are 323g...other then that they're microfibre which is easier to clean in most instances.
Edit: Looking through PDS at the Valsport SG's i noticed these
Valsport Una Klassic S6 Black

They seem to have all the same qualities of the Una, but they're K-leather and if you dont mind spending 10 pound more, they seem like the better boot as k-leather is better then microfibre IMO.