let’s divide it in plus and minus for the working student option:
- Earlier graduation and possibility to join full time earlier
- More time for thesis
- More time to prepare for consulting interviews
- Missing a top brand on your CV
- Missing a back up option – you may get a full time offer as a backup in case you do not manage to get an offer from MBB+Roland Berger, and try again your applications in 1-2 years
- Missing more “real” consultant experience – the working student job would probably not allow you to cover projects with the same intensity
Thus, the working student option may be better if you want to have a chance to join earlier, or want to have more time to prepare for interviews. The internship option may be better if you want to strengthen your CV and add a back up plan.
In general, the internship option may give you an advantage for the additional brand on your CV, you should consider though whether that would be worth the additional time required to reach that. In the end, both the options may allow you to get an interview with MBB and the ideal path to follow would depend on your priorities.
Hope this helps,