I got one used about a month ago. I really like it so far. I mainly stick on the 2290 setting. Space and tube are also very nice.
I need to update the firmware, not sure if that has been done. I do have a few annoyances with the flashback x4. First when you apply power to the pedal it turns on the delay, doesn't matter whether the delay was left on or not. Just a pain to have to hit the footswitch to turn it off. Second, when using the looper, the last delay used is always on, I have to turn down the delay level and then everything is fine.