Compared to Doha, Dubai has:

1. More nightclubs and nightlife.
2. More nationalities, less locals.
3. More buildings.
4. More Business/Trade.
5. Extremely bad traffic (Qatar's traffic is getting just as bad).
6. Bizarrely Dubai's Internet services are more restrictive (I noticed flickr and skype are banned there!).

I don't know which of these are better or worse, you be the judge.