By default, the Lamdbda MOO core database implement object quota, i.e. each object created takes 1 quota. Typically a new receives about 7 quota allowing him to build 1-2 rooms, 3-4 exits and 1-2 additional objects. Byte quota measure the total amount of space the user's objects occupy. A frequent figure of initial quota is 25000. So far, we haven't seen CPU quota (how much time verbs, i.e. procedures take to execute).
Both systems have their advantages and disadvantages. Byte Quota certainly mesaure in a more accurate way what space (i.e. how much memory) a user takes. However, Byte Quota may incite users to save space omitting textual information (help texts, descriptions of rooms an so forth) in order to save space. However, since quota increments are handled by the MOOs administrators (wizards) this factor has to be taken into account in various ways. I.e. more quota should also depend on the quality of textual information.