The problem with limit is the programming overhead in frontend and backend.
If you want a performance advantage you must parse the limit-params and select only the needed fields from db and send them to client. But this make the backend complicated.
If something is misspelled (frontend/backend) you need more time to find the error.
It is easier and cleaner provide some additional calls for specific data (like lastLogin).
If you use something like Backbone in frontend, you are happy to access all needed data so easy, why restrict them?
Ok if you have an heavy used performance critic application, you can start optimizing. But why, welcome to the cloud, add some processes ;-)
If you want a performance advantage you must parse the limit-params and select only the needed fields from db and send them to client. But this make the backend complicated.
If something is misspelled (frontend/backend) you need more time to find the error.
It is easier and cleaner provide some additional calls for specific data (like lastLogin).
If you use something like Backbone in frontend, you are happy to access all needed data so easy, why restrict them?
Ok if you have an heavy used performance critic application, you can start optimizing. But why, welcome to the cloud, add some processes ;-)