Firstly, you stated that the brighter pupils would gain access to an enriched education, however, you then state that the less able pupils would receive a more practical education. How is an academic and theoretical education better than a practical one?
Secondly, no, the 11+ should not become common place in schools once again as it reverts back on the whole policy of equal opportunity and equal rights. By bringing it back we would be taking a step back in this direction.
Also, would it not be better to encourage some of the pupils who perhaps don't achieve well in an academic sense?
Finally, intelligence is very malleable, especially during our younger years. Someone at the age of 11 might not be very bright and might not pass such a test. However, they might end up becoming brighter as they age. For example, they may have been a slow developer but are able to catch up later on. Surely bringing back the 11+ would only diminish the chances of success for many pupils.