Been done to death this one but i'll have my say as a beddiexwhippet owner.
Good points,
Better feet,better coat,stronger jaw,thicker skin,determination,courage,a nose that would put some hounds to shame,etc etc.
Bad point's,
Not as fast as a pure whippet,can be stubborn,selective hearing,some yap,and a refusal to back down even when the odds are stacked against them.
Each to there own and you pay your money and make your own choice.I chose a beddiex simply because i think its better suited to the ground i work.