I am afraid that I have to agree.
I too have run campaigns on Yahoo for the last 5-6 years and the amount of technical issues they have suffered from, even compared to 2nd tier ppc platforms in the UK is quite simply astounding, let alone compared to adwords which I have found to be incredibly reliable compared to Yahoo.
From my experience the data being assigned to unavailable or new terms in the category reports has been an issue that Overyoo just cannot fix - I have seen this several times over the last two years. I have recieved corresspondence from Yahoo in regard to this problem and they admitted to me that it was something that they are aware of and have been trying to fix! How long does it take to fix..clearly...a loooooong time!
This is apart from the slow bid updates on their own network and to third parties, the fact that I have to very often, log out of my account and log back in to see if the changes that I have made have been registered in the system, at times, incredibly slow editorial process and what appears to be somewhat randomly based editorial decisions!
Well I really hope that Panwords ( couldn't help it :) )is a system that Yahoo will be proud to represent themselves with.
From what I have seen of it and what Yahoo have said about it...there is alot that Yahoo have done towards having a stable, flexible ppc system.....bring it on...can't get any worse....can it?