Horrible swing, yet low handicap.

The only thing that matters is where the clubhead is at impact,every club i've been a member of has plenty of golfers with text book swings,that have cost them £££'s in lessons and equipment,yet they couldn't hit a barn door with a shovel !!!
If somebody is shooting consistently low scores with what some people perceive to be a "horrible" swing,it's obviously not horrible,its "effective" !!!
Furyk,Jimenez,Perry,Lehman etc etc,are there swings horrible,or effective ?