Which fermentation lock is better?

[Guest guest]

Which fermentation lock or air lock(same thing) is better for most

purposes? Which is generally more reliable, sturdier and more

difficult to break? The S-shaped 1 piece fermentation lock -

http://www.baderbrewing.com/graphics/00000004/s%20shaped%20air%20lock.JPG

Or the 3 piece fermentation lock? - http://www.ejwren.com/catalog/1463.jpg

Also, is it a good idea to us vodka instead of water in the

fermentation lock, in case the ferment sucks in the fluid from the

lock? Thanks.