What's the difference between these conditions?

Is there any specific difference between these conditions?

1) 
   begin
     acct = 1
     return 0
   end unless self.l_acct.nil?

2)
   unless self.l_acct.nil? 
     acct = 1
     return 0
   end    

From stackoverflow

• Yes; the former is bad practice, the latter is not. They both accomplish the same thing.

  Andrew Grimm : Bad practice because it's harder to read?

  Johannes Gorset : @Andrew Grimm: Yes, exactly.