I would use the currency in which your expenses are to play it safe. If you want to trade FX, you can still trade FX with your income without locking yourself in a potentially bad deal.
Also, I consider the USD to be a lot stronger long-term than the EUR.
Just look at the reaction of the European Central Bank vs the FED. It did raise interest rates pretty late and can't increase them too much since the southern states would then fall apart because of their debt.
Imho, the Euro is hanging on a thread. I am not sure if it will survive the next 5-10 years.