We had been waiting several months to learn how hard CERN would push the LHC for its initial running after repairing the damage from last September’s catastrophic event – now we know:
3.5 TeV per beam is half of their design energy, but still > 3 times the Tevatron beam energy. Personally, I think it is prudent to be cautious and advance slowly as they gain experience and confidence. The accelerator operators need to test many new systems and verify their reliability for the longer term. At this point, establishing some operational baselines for both the accelerator and the experiments is more important than pushing the energy and risking another incident causing extended downtime. You can’t do the physics if you’re not running. The performance will improve thanks to hard work from many people – I’ve seen it happen here at Fermilab.