I went with a clone because they're about £4/$6 and that seemed like a no brainer. I haven't had any duds yet! They only come in the 5V option from what I've seen, but it's simple enough to swap out the crystal and the regulator to make it a 3.3V/8MHz.
Only issue I had was to modify the LUFA DFU bootloader to automatically start the micro if there isn't a programming request within 5 seconds. The default code will sit in the bootloader forever until something happens - fine for prototyping, but a problem if you have it in a semi-permanent place and the power goes.
Thanks for the info. Where do you get them at £4 a pop?
Not worried about the bootloader problems as these would be prototype only and the voltage is ok as I'm replacing a PLC implementation with some homebrew kit so it's just switching relays and reading opto-isolated inputs, neither which are voltage sensitive.
Only issue I had was to modify the LUFA DFU bootloader to automatically start the micro if there isn't a programming request within 5 seconds. The default code will sit in the bootloader forever until something happens - fine for prototyping, but a problem if you have it in a semi-permanent place and the power goes.