None, because I learned from all. And the cheap ones I didn't like like the Argus brick, cost less than a roll of film and developing it. The expensive ones like the Canon VT can be resold for what I have in them, mostly. I don't mind learning what I don't like, if it doesn't cost money. I knew not to buy the used M9 I was offered, when their prices were going down, and I don't buy brand new cameras when they are first out. Either way, if you don't like them, you wasted money.