Just one word: super! Works like a charm and looks very good. Had some issues configuring the extension, Andrey replies in no time and helped immediately. Never had this level of service! Wanted to filter on the standard K2 rating as well. Not on the rating you need to give since it is linked to an extrafield value, but filter on the rating visitors of my website give to products. He personally customised the extension and make it work super! 200% worth the price!