Soz mate,
Well firstly the vaughan sig is very well made i think its best of these last 3 sigs, on that you could improve by sorting out the colouring of the render, its too redish atm if you know what i mean it should be a little greyish too just to go with the greyish BG.
The Risse one is good but i feel pool badge should be little opace you know and also riise render have another desaturated render layour because atm he is too bright and the smart blur doesnt look good on him.
The Villa sig is very good esp the BG and the pic on the right side but the actual render in middle doesnt work to the effect... maybe also desaturate it a little bit and colour it just slighlt like the BG..
Thx