These are the rings in my A5 pink Finsbury, they don't have any big gaps and the only problem I have with them is sometimes the pages get caught slightly, but I'm aware of that and try to be gentle. I have seen some horrific rings on Flickr and the Facebook group which has slightly made me nervous to buy anymore Filofaxes.
Another problem which I have lucky not had experience with is training a Filofax to lay flat. I have heard a lot of Filofax owners complain about certain designs that won't lay flat and they have to put heavy vases and boxes on them to 'train them'.. I don't know why that is, I've personally never had to train my Identity or Finsbury, so maybe I've been lucky. I don't know whether it's just the personal size which suffers from this problem because I've not seen any A5's being trained. If I had to train my Finsbury, I think I would lay it face down and put something heavy on both sides for a few days, if that didn't work I would send it back and request a new one.
Let me know your Filofax experiences and any other problems you've ran into :)