Unlimited Tablespace, Roles and Pitfalls

Greetings All,
Which is the better, "Real World" way of managing Quotas?

• Leaving Unlimited Tablespace granted for each [application] account?
  This effectively removes quota management, but that sounds too good to not come with problems of its own .... any idea what they might be?
  
  
• Granting unlimited Quotas to each [application] account on every Tablespace in which that account can create data?
  

In one of my databases, I could have twenty or more application accounts creating data on behalf of hundreds of users.  I'm not overly worried about limiting them within the tablespaces that they can legitimately update, but should I be worried about 'Unlimited Tablespace's "global" nature?