Never done dexedrine but it is generally prefered because it contains only the d isomer of amphetamine. Adderal also has the l isomer, which doesn't get you high, but causes unwanted peripheral affects. That's for recreational purposes, for ADD it may be somewhat different.
after 5 years adderall just doesn't give me much euphoria anymore and taking breaks is hard after 5 years of use with withdrawls and all.
On a side note what does op mean? couldn't find anything to explain it and don't want to start a new thread for an easy question like that seeing as almost everyone says it