Bitcoin.de is not really an exchange, it is more an escrow that facilitates trading: you deal directly with other users and you buy/sell using SEPA transfers. Once the payment is received by the you/the other party, Bitcoin.de release BTCs accordingly.

Pro:
- Transfers are not stuck in a limbo depending on non-specified "problems" (MtGox/Bitstamp style).
- Because the entities involved in the transfers are banks, transfers really happen in 24/48 hours
- The price for BTCs sometimes is lower than "real" exchanges
- You don't need to fully verify your account: there is a semi-verified status that allows you to trade a maximum of €2500/year (IIRC there is also a limit in terms of volume, but at the moment I am too lazy to login and check ).

Cons:
- Because of the 24/48 hours delay you cannot do day trading
- No major charting facilities available
- In case of a price crash the other party may refuse to honour the transaction (by doing so s/he will be penalised and possibly banned by/from bitcoin.de)
- Prices in USD don't make any sense: they are hugely overestimated