I have had a few cars in the past with EGR's disable (or just not working), but none of them made a big enough difference in performance to worry about it. The amount of EGR flow allowed is so minor that it really isn't an issue. Also...most EGR systems only allow flow unde rpart throttle cruising conditions. So idle performance is not effected, nor is full throttle performance.
The only thing you do by unhooking it is create more NOx, which in turn forms smog. Kind of a lose lose situation.