Van,
I hold the FAA/IR but have a number of friends who hold the JAA flavour and a few who have JAA and or FAA ATPLs. There is a fundamental philosophical difference between America and Europe on the knowledge side. In Europe, there is a view these things should be structured qualifications at professional schools. In the US it is that you need to know and demonstrate the application of the knowledge in the real world and they don't really care how you got the knowledge. In Europe, there is an element of knowledge requirements to make it more time consuming.
However, and many people seem to ignore it, I am confident the key objective of FCL.008 was not to save the IMCr but to make access to the IFR system more attainable while not reaching so far as to create something that could not be sold across Europe (which like it or not is what happens when your government agrees to regulate aviation on a pan-European basis).
The flying tolerance are broadly similar with a couple of areas where the JAA/IR is tighter than the FAA/IR, however, the FAA then make type rated pilots (i.e. everyone in a large or turbojet aircraft) fly to higher tolerances in the ATPL exam (and these are slightly tighter than the JAA tolerances). However, anyone who is doing real IFR approaches should be flying to this tolerance anyhow. As several people have pointed out, the weather can always go down hill and an EIR pilot may not be able to do a cloud break and have to land off an emergency ILS, and IR pilot may have what he thought was going to be 600 and 1 mile go down to 200 and RVR700 - and you want to be able to hold it together when that close to the ground.
Many of the comments that have been made seem to be reflect aspect of what I believe is being created in terms of making the IR more accessible. However, there was a view, which by the comments on this thread seems to have been misguided that a stepping stone rating between the PPL and a streamlined competency based PPL/IR was necessary for PPL's to feel they can approach the instrument flying learning curve and backstop the save the IR plan. If there is no interest across Europe in this stepping stone, I would imagine it would simplify FCL.008s work to drop it and focus on a streamline IR and hope AOPA UK comes up with the goods for a UK opt out to keep the IMCr.