Yup, its a tough call - expensive Italian chrome or Chinese alloy at less than half the price for the same functionality and more...
If the Breville had been about when I bought my Rocket, the decision would have been very difficult and I guess that the price I paid second hand for the rocket was low enough to make me make the leap from the em6910, and I am very happy with the rocket.
Of course, if you do go for the Breville, you can afford a roaster too. Everyone should have an iCoffee in the shed even if only to roast an occasional single origin to impress the neighbours.
One final thought - Once you buy a top end machine, every poor drink you make becomes your fault, not the machines. There is some comfort in NOT upgrading!