I find that Hungarian smells like rotten eggs and it less corrosive
Czech smells fine and comes on stripper clips but is 'corrosive as sin'
6 of one 1/2 dozen of the other, I'd say buy whatever is cheapest. I currently am using a little of both and I see no noticable difference in accuracy or reliability.
BTW, whoever first used used the phrase 'corrosive as sin', I apologize for stealing it. It just sounds too damn good to me