I have a lifetime supply of ergo 4000's stashed away since the day they announced they were discontinued.
Down to 3 Natural Pros :(
The failure point on every ergo 4000 I've owned has been the spacebar center post. First thing I'll do now is grease that up with some Teflon marine engine grease. Did that on the current one and I'm at around 6 years without a failure vs 2 or so before that.