This question has popped up a few times and the answers tend to be along the lines of.
"They are of lesser quality and the saving of initial purchase we be short lived as you buy replacement parts for the parts that fail."
"I you have that sort of money rocking mate pick up a decent 2nd hand one"
And my personal Favourite
"nah they are S&&T mate, don't buy, uninformed gibberish, no explanation of opinion....yeah they poo!"